People say they care about the "story" behind the PR. But no one cares about that story if it's about forgetting to fix a test and a typo in a comment.

The extra commits are just noise that make you think the original commit is a source of truth in a blame when it has been amended 3 times more in the same PR, but the link isn't apparent anymore.

Force pushing is bad to a published branch, not a feature branch (not that you really have force pushes in Gerrit anyway). There are versions of Gerrit tooling where you can have a branch as dirty as you want locally, but only the final aggregated change is visible for review of that's what you prefer too.