Undoing a commit that is already pushed

Revert. It creates a new commit that undoes the change and leaves everyone else's history intact. Reset plus force push rewrites what others have already pulled, which turns your small mistake into everyone's afternoon.

Marginally. The real value of rebase is a readable history when many branches land per day. With two people the cost of the occasional botched rebase usually exceeds the benefit, so merge and squash on the way in is a calmer default.