I didn't mean after you logged in... I meant as the default login option to a new Linux box.

Ah ok. I misunderstood.

As to the other bit, Google hasn't disallowed passwords and I don't think we're at a point where they would.

But I mean ideally you have multiple PassKeys so if you lose one or you computer/phone dies you have a backup.

I keep a hardware key in a safe that can be used as a backup key to my accounts