I shared your sentiment maybe a year+ ago when it comes to css, and I do think it's one of the areas AI in general struggles with (where art and code meet), but it's a lot better today with the latest OpenAI and Anthropic models as someone that works on design systems for a living (for now). It follows stylistic patterns, it can inspect the issue in the browser and have a better understanding of CSS upstream effects than it used to (it used to suck at this and paint itself into a corner over and over like some game of whack-a-mole), and can even tackle things using latest interop features.

It does make really silly mistakes now and then, like using fallback css variables in the wrong order, but they are fewer and farther in between.

"I believe the best web platforms will heavily invest in human crafted UI/UX because that is what will make you stand out. The rest will get thrown on the slop pile and forgotten."

Agreed!