> The big blocker is a lack of confidence that someone won't ask me to drastically rework my PR.

Another big blocker is the confidence to delicately review a PR and demand it to be drastically reworked.

Actually, I think they're the same problem.

When your livelihood is tied to other humans, you generally want to minimize conflict.

Not really the same thing. The point is that if someone wants you to totally rework the base PR then the follow-on work will need to be redone.

There are also control freak psychopaths in our midst who just love telling people what to do and exercising control. They don't really know anything about producing quality software, but they sure know how to tell people they're wrong.