The pull request has always been the place where every concern about a change converges. Tests run. Linters run. A reviewer reads it. Someone clicks merge. For most of the history of this practice, the PR was treated as a light, conversational artifact: a place to talk about a change before it lands.
That was fine when the throughput of changes was set by humans. With agents in the contributor pool, the PR has to do more work. It is no longer the casual handoff between author and reviewer; it is the last point before a change enters the system where every quality concern can still be enforced. It is, in the strict sense, a checkpoint.
Most teams have not updated their PR practice to match.
What "load-bearing" means here
A PR is load-bearing when the system trusts it to be the place where standards are enforced. The required checks have to actually represent the standards. The template has to actually surface the questions a reviewer needs to answer. The merge rules have to actually prevent the bad cases.
