Well, many reasons

For starters, its uncomfortable to wear for long periods of time, the weather also could be a factor as where I live, its either burning hot or freezing cold which neither is ideal for wearing suits.
I also don't really have the confidence to dress up like that in public.
To me, dressing up in a tie, vest and shit is better as a hobby or for special occasions.

Its also a hassle to get dressed as it takes me about 20 minutes to get dressed


But if everyone started dressing like this again, I wouldn't be against it. men, woman, everyone looks great in a suit (imo)