Hmm, that doesn't match my experience. If I remember correctly, I've mostly seen long-running branches where the conflicting code was moved/taken care of still having rebase conflicts because git is running the commits one by one, and is conflicting with the old commits (before they were fixed), requiring me to fix them yet again.

Merging doesn't have that problem, it usually just merges fine unless there are conficts in the latest commit (not all previous ones).