GPT-4o/GPT-5 complaints megathread - A Developer's Story

GPT-4o/GPT-5 complaints megathread

A Developer's Story

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The Great GPT Regression: Why Developers Are Revolting Against OpenAI's Latest Models

The Hook

Something strange is happening in the AI community. Developers who once evangelized GPT-4's capabilities are now flooding forums with complaints about its supposed successor. The r/ChatGPT megathread with nearly 4,000 engaged users isn't celebrating breakthroughs—it's documenting what many see as a dramatic decline in model performance. This isn't just another case of users resistant to change. Senior engineers, AI researchers, and production teams are reporting that GPT-4o and the rumored GPT-5 behaviors feel like significant steps backward. When your cutting-edge AI tool starts forgetting basic context mid-conversation or refuses to complete tasks it handled effortlessly weeks ago, you have to wonder: what exactly is OpenAI optimizing for, and why does "advancement" feel like regression?

Background: The Promise and the Product

To understand the current revolt, we need to revisit what made GPT-4 revolutionary when it launched in March 2023. It wasn't just the model's raw capabilities—though its ability to pass the bar exam and write functional code certainly impressed. GPT-4 represented a reliability threshold that made AI assistants genuinely useful for professional work. Developers could trust it to maintain context across lengthy debugging sessions, architects could iterate on complex system designs, and writers could collaborate on nuanced technical documentation.

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The model's consistency was its killer feature. Unlike GPT-3.5, which would occasionally hallucinate entire programming languages or forget crucial details from earlier in a conversation, GPT-4 felt stable. It became the backbone of countless developer workflows, integrated into IDEs through GitHub Copilot, powering documentation systems, and serving as a reliable pair programmer for solo developers and large teams alike.

When OpenAI announced GPT-4o (the "o" standing for "omni") in May 2024, the pitch was compelling: multimodal capabilities, faster response times, and improved efficiency. The model would handle text, vision, and audio natively, promising a more natural interaction paradigm. Early demos showed impressive real-time conversation abilities and sophisticated image understanding.

But something happened between demo and deployment. The complaints started as whispers in developer Slack channels: "Is it just me, or is ChatGPT getting dumber?" By late 2024, these whispers became a roar. The r/ChatGPT megathread isn't an anomaly—it's the tip of an iceberg that includes GitHub issues, Twitter threads from AI researchers, and increasingly frustrated enterprise customers questioning their OpenAI commitments.

Key Details: The Regression Reports

The complaints clustering in these megathreads paint a disturbing picture of degraded capabilities across multiple dimensions. Developers report three primary categories of regression: cognitive performance, behavioral changes, and reliability issues.

On cognitive performance, users describe a model that seems lobotomized compared to early GPT-4. Code that once compiled on the first try now contains basic syntax errors. Mathematical computations that GPT-4 handled with ease result in obviously wrong answers that the model confidently defends. One software architect documented their attempt to use GPT-4o for system design—a task they'd successfully completed dozens of times with GPT-4. The newer model couldn't maintain consistency across a basic three-tier architecture description, contradicting itself about data flow within the same response.

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The behavioral changes are equally concerning. Users report excessive safety filtering that borders on the absurd. Requests to debug authentication code get flagged as potential security violations. Attempts to discuss historical events trigger content warnings. One developer shared a screenshot where GPT-4o refused to explain how a rainbow forms, citing "potential harm." While safety is crucial, the implementation appears to have swung so far toward caution that it's undermining the tool's utility.

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Perhaps most damaging for professional use cases are the reliability issues. Context windows—supposedly larger than ever—seem to have amnesia. Users report the model forgetting crucial details from just a few messages back, requiring constant reminders and restatements. The infamous "lazy December" phenomenon, where the model would refuse to complete tasks claiming it was "just an AI," has evolved into something worse: a model that appears helpful but subtly fails to follow instructions, requiring multiple attempts to get basic tasks done.

Quantifying these regressions is challenging because OpenAI doesn't publish detailed benchmarks for production models. However, community-driven testing tells a stark story. The popular "SimpleQA" benchmark, maintained by independent researchers, shows GPT-4o scoring 15-20% lower than GPT-4 on basic reasoning tasks. Code generation benchmarks are even more damning, with success rates on HumanEval dropping from GPT-4's 67% to GPT-4o's reported 52%.

What makes these regressions particularly frustrating is their inconsistency. The model might brilliantly solve a complex algorithmic problem, then fail at basic string manipulation. This unpredictability makes it nearly impossible to rely on for production workflows where consistency is paramount.

Implications: The Hidden Cost of Efficiency

The degradation pattern points to a fundamental tension in AI development: the trade-off between capability and efficiency. Multiple industry insiders suggest that GPT-4o's regressions aren't bugs—they're features, designed to reduce computational costs while maintaining the appearance of advanced capability.

This theory gains credence when examining OpenAI's business model. Running GPT-4 at scale is enormously expensive, with estimates suggesting costs of $0.03-0.06 per 1,000 tokens. When you're serving millions of users making billions of requests, even small efficiency gains translate to massive cost savings. The introduction of GPT-4o coincided with OpenAI making ChatGPT freely available to all users—a move that would be financially catastrophic without significant cost optimizations.

For developers, these efficiency optimizations manifest as a less capable tool masquerading as an upgrade. The multimodal capabilities, while impressive in demos, don't compensate for degraded text performance in real-world use. A developer debugging Python code doesn't care that the model can now analyze images if it can't reliably track variable states across a function.

The implications extend beyond individual developer frustration. Companies that built products on top of GPT-4's capabilities are finding their applications breaking in subtle ways. Customer support bots become less helpful, code review tools miss obvious bugs, and automated documentation systems produce inconsistent output. The API pricing hasn't decreased proportionally to the performance degradation, meaning businesses are paying the same (or more) for inferior results.

This situation reveals a broader problem in the AI industry: the lack of transparency around model changes. OpenAI doesn't version their production models in a way that allows developers to pin to specific capabilities. You might wake up one morning to find that your carefully tuned prompts no longer work because the underlying model has been silently "optimized." This uncertainty makes it nearly impossible to build reliable systems on top of these APIs.

What's Next: The Fork in the Road

The community's response to these regressions will likely force a reckoning in how AI models are developed and deployed. We're already seeing several trends emerging that could reshape the landscape.

First, there's a growing movement toward open models and self-hosting. Llama 3, Mistral, and other open-source alternatives are gaining traction not because they match GPT-4's peak performance, but because they offer consistency and control. Developers are willing to accept slightly lower capabilities in exchange for predictability and the ability to version-lock their dependencies.

Second, we're witnessing the emergence of specialized models over generalist ones. Instead of relying on a single model for all tasks, developers are increasingly using purpose-built models for specific functions—CodeLlama for programming, specialized models for SQL generation, and fine-tuned models for domain-specific tasks. This approach sacrifices convenience for reliability.

The pressure might also force OpenAI to reconsider its approach. The company faces a classic innovator's dilemma: optimize for efficiency and risk losing developer mindshare to competitors, or maintain quality and accept unsustainable costs. The recent megathreads suggest they've pushed too far toward efficiency. The question is whether they can course-correct before developers abandon the platform entirely.

Looking ahead, the GPT regression saga might mark a turning point in AI development. The era of blind trust in ever-improving models is ending. Developers are demanding transparency, versioning, and guarantees about capability preservation. The next generation of AI tools will need to balance advancement with reliability, offering clear communication about trade-offs and giving users control over which optimizations they accept. The companies that recognize this shift—whether OpenAI or its competitors—will define the next phase of AI integration in professional workflows.

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Written by Andrew • January 25, 2026