I never use GPT for anything other than amusement like asking it to write a story about living in the hood but in the style of a grumpy old man being the narrator.
In the past and to some degree to this day, I work(ed) in copywriting. The people in that industry were very concerned that AI was going to took their jerbs! But as it turns out the use of AI in this field is very strongly frowned upon and anyone using it that gets caught could find themselves blacklisted. There are tools to detect it's use as well.
It is interesting that you were quickly able to determine what was AI driven though, I haven't messed around with it enough to really notice.
You know where I find it most useful? Say you have a programming problem that you are having trouble articulating in order to do a google search. GPT is a little closer to understanding what you mean like a real person and can get you started writing a function or working your way through solving your problem. Don't expect it to write completely valid code, most of the time though. I have found that really useless.
I think my brain sort of automatically starts doing pattern matching. Probably from so many years of writing code. But it's not really that clever, I think. The voice that it speaks in has a sort of 'ad' like feeling. Like it's trying to sell you something.