rerere is still useful here to handle merge conflicts after repeated rebases.

As someone who tried rerere and didn't see the point:

How? Usually I rebase the same branch multiple times onto different, but successive commits of the master branch. But after I solved a bunch of conflicts of the first rebase, I shouldn't have the same conflicts again in a second one, since the rebased branch contains the merged conflict. Rebasing again could only turn up new conflicts (with newer, other commits on the master branch).

How can I have the same conflict again for repeated rebases?