Of course I commit a lot of garbage commits that don't work, it's super useful to do so. Those never get pushed out into branches that I share to others though

Of course I commit a lot of garbage commits that don't work, it's super useful to do so. Those never get pushed out into branches that I share to others though - why would I waste their time having them look at those? What I push out are atomic commits that make sense logically, not an external undo log of my text editor; squashing those on merge provides no benefit and only loses useful information. Squashing should happen before push, not on merge, and there's no reason to have buggy "intermediate" commits recorded in your central remote branch at all.