The problem is really behavioural, not the tooling. People that do not understand, test and document their decision making in their PRs should not be submitting them, regardless of what tooling (AI or otherwise) they used to create them.

This problem existed before AI, but it is now just worse due to the spamming nature of these "contributors". It's another form of endless September where people unfamiliar with the norms of team software development are overwhelming existing project maintainers faster than maintainers can teach them the norms of behaviour.

In the end, some sort of gatekeeping mechanism is needed to avoid overwhelming maintainers, whether it's a reputation system, membership in an in-group, or something else.