I would say the exact opposite. Let the machine do the easy/simple/boring stuff. Let the human peer reviewer do the big question. That's what the human is good at and excited about and it's what the machine will not be good at. The question is a philosophical one: Is this a good idea? Is it relevant? Is it important? This is highly subjective and needs folks in the field to build consensus about. Back in my PhD days, I'd have loved if a machine could have taken care of the simple stuff so humans could focus entirely on the big questions.
(A machine could point to similar work though.)
You raise a good point overall. I was just trying to respond to the idea of it replacing a human entirely, as if the authors submit it to the system and a journal editor has to made the decision to publish it or not. I would love to focus more on the big picture stuff, but in my experience most peer reviews amount to "Could you phrase this different?" rather than "Is this a good idea?". I think the latter is a much better better question to ask.
It makes sense to have the AI do the boring stuff, but don't frame it as a peer reviewer, because that's not what it is.