You can get an AI to produce a 10/10 design trivially by taking an existing 10/10 design and introducing variation along axes that are orthogonal to user experience.
You are right that most people wouldn't know what 10/10 design looks/behaves like. That's the real bottleneck: people can't prompt for what they don't understand.
Yeah, obviously if you're talking about copying/cloning, but that's not what I thought the context here was, I thought we were talking about LLMs themselves being able to create something that would look and feel good for a human, without just "Copy this design from here".
You are right that most people wouldn't know what 10/10 design looks/behaves like. That's the real bottleneck: people can't prompt for what they don't understand.