Many of the people who submit 9000-line AI-generated PRs today would, for the most part, not have submitted PRs at all before, or would not have made something that passes CI, or would not have built something that looks sufficiently plausible to make people spend time reviewing it.

9000-line PRs were never a good idea, have only been sufficiently plausible because we were forced to accept bad PR review practices. Coding was expensive and management beat us into LGTMing them into the codebase to keep the features churning.

Those days are gone. Coding is cheap. The same LLMs that enable people to submit 9000 line PRs of chaos can be used to quickly turn them into more sensible work. If they genuinely can't do a better job, rejecting the PR is still the right response. Just push back.