... what? `rebranch` isn't a command in git? I think you mean rebase, and
sure, if you were rebasing the
entire
history it would be slow and awful. But don't do that. Rebase at like `HEAD~10` (or whatever) to only clean up the last 10 commits. There's no performance issues or even management issues. Maybe go read the rebasing section (
https://git-scm.com/book/en/v2/Git-Branching-Rebasing) of the git manual...