What pull request review is actually for
In most teams the pull request is where review is supposed to happen and is not really happening. A reviewer opens a diff of four hundred lines, scans it, sees nothing obviously broken, and approves. That is not negligence, it is the honest limit of attention on a Tuesday afternoon.
The result is that the mechanical pass, the one a machine is genuinely better at, never gets done, and the judgement pass gets done badly because it is competing with the mechanical one for the same attention.
A specialist review posted before a human opens the diff separates the two. What is left for the person is the part that needs a person.