I am a frontend engineer and I see so many bugs from vibe-coded CSS from people who think just like you. CSS is very powerful and easy to get wrong if you don't understand it. Since most CSS code on the internet is not good, LLMs do not generate good CSS code and create a lot of bugs ranging from bad performance to completely broken reflow.

Funnily enough, I seem to remember some people saying that compiler generated assembly wasn’t as good as handmade assembly.

the question is, what's the business cost of some amount of css bugs vs paying specialists or people to learn these details.

the generalists win overall, except of course for specific cases where specialists are great