Is this the case even with rerere in git?
My anecdotal experience is that I indirectly need/benefit from rerere much less often because I'm not usually resolving the same specific conflict more than once. I fix it the one time and then jj is rebasing a whole lineage for me, starting from the early commits, not from the single-branch leaves. That way I don't get "I rebased one branch and fixed this one already, but now I have to do it again for a second branch that shared the same conflicted commit as the first."
By contrast, git rebase --update-refs does not handle sibling branches but detaches them instead, and git replay hasn't had much TLC for UX yet. Plus, the last time I tried replay it was still obliterating commit signatures.