Public transport works well when your city prioritizes it. I spent my youth living in places that don't and I literally cannot imagine going back.
And when there is critical mass. Public transit works in dense urban centers, because it's less worse than driving and parking. It doesn't work in smaller towns. There, it just becomes something that everybody pays for but a tiny minority of people ever use.
I've noticed it got cleaner after COVID happened. Before COVID... It was world's most disgusting subway I ever been to: filthy, sketchy and leaks rust on your head.
Litteraly where I stopped believing you.
It's dirty. Only DC has a somehow-clean subway, which stands out as a nice exception to the rule.