The current versions is close to the original 3.5 version, while 3.5 has become horribly bad, such a scam to not disclose what's going on, especially for a paid service.
The fact that rumors about GPT-5 were quickly suppressed and the models were dumbed down even more cannot be entirely explained by excessive demand. I think it's more likely that GPT-3.5 and GPT-4 demonstrated unexpected capabilities in the hands of the public leading to a pull back. Moreover, Sam Altman's behaviors changed dramatically between the initial release and a few weeks afterward -- the extreme optimism of a CEO followed by a more subdued, even cowed, demeanor despite strong enthusiasm from end-users.
OpenAI cannot do anything without Microsoft's data center resources, and Microsoft is a critical defense contractor.
Anyway, personally, I'm with the crowd that thinks we're about to see a Cambrian explosion of domain-specific expert AIs. I suspect that OpenAI/Microsoft/Gov is still trying to figure out how much to nerf the capability of GPT-3.5 to tutor smaller models (see "Textbooks are all you need") and that's why the API is trash.
the one from a MS researchers that has been recommended to all of us probably. Good video btw.