Hum... I imagine LLMs are better than every developer on getting CSS keywords right like the GP pointed. And I expect every LLM to be slightly worse than most classical autocompletes.
Getting CSS keywords right is not the actual point of writing CSS. And you can have a linter that helps you in that regards. The endgame of writing CSS is to style an HTML page according to the specifications of a design. Which can be as detailed as a figma file or as flimsy as a drawing on a whiteboard.
This is like saying that LLMs are better at knowing the name of that one obscure API. It's not wrong, but it's also not the hard part about CSS