I misspoke in my comment and must have used Swing more than JavaFX (I’ve used both, but forgot which one I primarily used, this was 8 or 9 years ago and a short job). Either way, I really don’t like when only a subset of the language is supported, because then it becomes a constant guessing game of whether or not something is supported. In the case of JavaFX, there are a few features not supported and a couple gotchas mentioned in their docs.

And I think vanilla CSS is not that bad. I definitely don’t think it’s bloody awful. Most wrappers around the language added variables and nesting. CSS now supports variables and I think it even supports nesting :)

There’s probably other features that could be good, but for a language that’s just meant to provide style metadata for my UI, CSS works fine.