I don't believe this is how it is actually implemented in _most_ companies. Where I work every PR must have a linked story / bug / etc but anyone has the rights to create a story so it acts more as a way to track what changes actually goes into a release for x-teams to review and see if they need to document it, etc.
In regard to refactors, people tend to just squash them into another change they are making. This makes the git log a bit harder to follow at times, but people did this back when we just used to push to trunk too so I don't think the story is the deciding factor.
In regard to refactors, people tend to just squash them into another change they are making. This makes the git log a bit harder to follow at times, but people did this back when we just used to push to trunk too so I don't think the story is the deciding factor.