ChatGPT is just a consumer of their identity/auth system though, same as their core product - the API. Considering ChatGPT came much later, it seems irrelevant.

I don't think their API is their core product. The chat application is not only used by more people, but it drives development of the API.

Drives more revenue too. But I still think in the long run, APIs will bring more revenue.

I’d say the consumer front end is more of an afterthought. It also seems like something they want to get rid of at some point so that they have to deal with the resellers like Microsoft did in the 90s with MS Windows

And yet it is still better than Gemini’s front end

All software is more hacked together than we want to admit.

The model might be fine (I have questions, but let's assume it's reasonable), but I don't think anyone could use the UI for more than a few minutes and not realize it was a hack job.

For one fun one, on mobile web (android/chrome) you can't insert a space in the middle of a "word" you created by deleting the space between two words. The deletion is immediately reverted by some JS abomination.

It's one thing to call that an unimportant bug, but it calls into question a whole chain of decisions leading to that moment, and it's far from an isolated incident. As always there's a relevant xkcd: https://xkcd.com/463/