I don't usually want to rewrite history. I just want the target branch with all my commits on top (I usually squash the feature branch into one commit anyway). I have yet to run into a situation where this isn't good enough.
If the branch diverges so much and has so many commits that this simpler approach doesn't work, that might not be a git problem, but a project management one. It's still always nice to know git has tools to get me out of a jam.