CSS is fine, actually
Every two years there is a fresh wave of complaint about CSS. Every two years CSS gets quietly better and the complainers move on to a different tool that they will, in turn, complain about in 2028.
I learned CSS in 2009 by reading the source of websites I liked. That still works. The websites are different and the properties are different but the method — view source, copy, modify, view source again — is unchanged. There are not many skills with that kind of half-life.
If you think CSS is bad, you might be thinking of the framework you’re using. Or the build tool. Or the team. CSS itself is, mostly, fine.