You are thinking about the unlocking. Apple thinks about the security, that is not allowing anyone other than you to unlock the iPhone. That's even more important. I'm sure someone would find a way to unlock your phone. For example, I take your phone out of your pocket and the watch authenticates it, while _I_ am holding it in your hand, not you.
And Apple made a change where when you look at your phone the phone decides _immediately_ that there is a person with a mask that cannot be recognised, and puts up the passcode immediately, so it's much faster now.