Expanding on that, the issue is aggravating the maintainers bottleneck, because how do you find new maintainers if you do not accept outside contributions?

Another option would be to make a contributor pay for the review of its PR, even a small fee, to deter AI-slop, at least for new contributors. It could/would exclude students or people with the lowest wage though, but I'm optimistic even a 1$ bill or less would be enough.