An interesting scenario I heard was a fellow in, I think, Colombia. He was visiting, and was looking at his phone on the sidewalk. As he was looking at it, a pair of people rode up on a motorcycle or scooter, grabbed it out of his hand, and drove off.

They just got themselves an unlocked phone.

I assume this protects, somewhat, against this by the fact that were the thieves to try and change anything, there's another step of verification necessary than there was before.

And I think it was very clever of Apple to leverage the device location as an ad hoc "2FA". "Something you know, some place you are."