The bottom of ChatGPT highlights which version is being used of GPT-4 and supposedly what version of ChatGPT it is.
> ChatGPT Mar 23 Version. (https://help.openai.com/en/articles/6825453-chatgpt-release-...)
It's possible to change the output both by tuning the parameters of the model and also client-side by doing filtering, adjusting the system prompt and/or adding/removing things from the user prompt. It's very possible to change the resulting answers without changing the model itself. This is noticeably in ChatGPT, as what you say is true, the answers change from time to time.
But when using the API, you get direct access to the model, parameters, system prompt and user prompts. If you give it a try to use that, you'll notice that you'll be getting the same answers as you did before as well, it doesn't change that often and hasn't changed since I got access to it.
Which is very interesting. You already have a model that consumes nearly the entire internet with almost no standards or discernment, whereas a smart human is incredibly discerning with information (I’m sure you know what % of internet content that you read is actually high quality, and how even in the high quality parts it’s still incredibly tricky to get figure out good stuff - not to mention that half the good stuff is actually buried in low quality pools). But then you layer in political correctness and dramatically limit the usefulness.