> AI agents can build a whole app and review PRs better than a lot of people

Assuming you're comparing to experienced human developers that are good at what they do, then I think you have to define what "better" means here. It's clear that you can get correctly functioning software faster in many cases, but it's not clear that the design will be better in terms of conciseness and readability or that it's as useful as a foundation for building upon later if nobody understands what's going on inside.