And you absolutely can stop people from doing that. Simply accepting dickish asshole toxic behaviour as "well, people are like that shrug" and never telling people off is exactly the problem.
If you go to management to complain about a coworkers behavior you may just be told that you have to adjust your expectations to get along with them
If there's a team agreement and someone continues to violate it then you actually have a complaint you can make to management that has some bite to it
The whole concept of a PR is to review the changes you ask your team to pull into the repository.
What do you think PR comments are intended to be? Pats on the back and public announcements on how awesome you are?
No, the whole point of a PR is to allow others to review the changes you proposed so that the mistakes you are trying to introduce are easier to spot and prevent.
What do you call comments that flag a problem with your code changes? Do you call it "being the problem"?
> If there's a team agreement and someone continues to violate it (...)
How will they tell if you do not point out those violations in the PRs? That's precisely why they exist.