Yeah, imagine you accidently commit over weeks of work, or hell, if it's the main branch, and you deleted the other origin branch prior to merging, it could be a lot more than a few weeks worth of work. The revert to a previous commit... shutters.
I don't know if you're joking, but in case you're not: git reflog and git reset --hard HEAD@{n} is your friend. You can undo almost anything. Deleted commits and branches aren't really deleted. Remotely deleted branches can be pushed again.
Except for an (accidental) git restore/git reset. Those are permanent and can't be undone.
Even git reset can be undone by a lot of editors. At least IntelliJ has an excellent local history that works much like git. Sure itโs a pain if you touched several files but thatโll teach you to atomify your commits.
Edit: Plus, git reset itself does nothing of note really, but Iโm sure you know. Needs the โhardflag to do any meaningful damage.