Just because one isn’t good at a thing doesn’t preclude one from being a sufficiently passable judge of a thing.
To wit, the answer pre-AI was to hire an expert on that thing, and you would then critically assess their work product, despite being unable to build it yourself.
True, but if you hire a generalist and they are consistently under-performing specifically in the subject matter where you are an expert, it may behoove you to take the rest of their work with a grain of salt as well.