On the topic of older (Claude) models being better... anyone knows anything close to 3.5 (or 3.6) era Sonnet? It was by far the best LLM I had ever asked my doubts too. It actually explained in a human way, not like some AI I need to re read thrice to understand.

(I've used modern Gemini 3.1 pro & claude too. Modern ChatGPT is just as useless, I've never heard a human speak in points. The human brain never encounters that irl.)

This was obviously a conscious choice from the leadership at he frontier labs, and especially OpenAI, considering how 4o turned out.

I don't think they expected the ELIZA effect [0] to explode as much as it did when they started including feedback directly from users into posttraining the next generation, so to be safe they've likely added several regimens of synthetic data ensuring ChatGPT tries to steer away from ELIZA.

[0]: https://en.wikipedia.org/wiki/ELIZA_effect