ChatGPT was always a research preview of a new tool they’d produced, which is a refinement of GPT-3, optimised for a specific purpose. Their intentions, when making this public, were effectively to let the public beta test this, and then make the refinements they needed to make in response to “bugs”/unanticipated features users discovered …
https://www.reddit.com/r/OpenAI/comments/zoez3p/is_it_just_me_or_is_chatgpt_getting_worse_by_the/