I don't commit as a backup. I commit for other reasons.

Most common is I'm switching branches. Example use case: I'm working locally, and a colleague has a PR open. I like to check out their branch when reviewing as then I can interact with their code in my IDE, try running it in ways they may not have thought of, etc.

Another common reason I switch branches is that sometimes I want to try my code on another machine. Maybe I'm changing laptops. Maybe I want to try the code on a different machine for some reason. Whatever. So I'll push a WIP branch with no intention of it passing any sort of CI/CD just so I can check it out on the other machine.

The throughline here is that these are moments where the current state of my branch is in no shape, way, or form intended as an actual valid state. It just whatever state my code happened to be in before I need to save it.