Hard disagree. There's more to UX than pushing pixels around. Usability, accessibility, and capturing the broader customer experience at 40,000 ft isn't a trivial process when you're designing a large product (or suite of products) especially.

These areas obviously tie into engineering very closely, but the thinking that goes into them happens at the design stage, at a lower cost than starting with engineering. AI models suck at getting every facet of this process right, because designers are achieving a balance between branding, usability, standards, taste, and differentiation -- the exact opposite of a model trained to reach for the most average outputs.