I tried living with just the Apple Watch instead of the Touch ID for a few months to see how reliable it was...
Sometimes it would take a few minutes in the morning before my Mac would even recognize 'hey, there's a watch' (typing in my full password was usually much quicker than waiting for the watch unlock).
Sometimes whatever notification happens that triggers the watch to vibrate and allow the double-squeeze-to-accept action would just... not.
Other times the above notification would pop up about 8-15 seconds after the prompt on the screen.
It was inconsistent enough I got _really_ good at typing my password, since it was normally quicker than waiting on the Apple Watch.
Contrast that with the Touch ID, that's always ready to go.
Sometimes it would take a few minutes in the morning before my Mac would even recognize 'hey, there's a watch' (typing in my full password was usually much quicker than waiting for the watch unlock).
Sometimes whatever notification happens that triggers the watch to vibrate and allow the double-squeeze-to-accept action would just... not.
Other times the above notification would pop up about 8-15 seconds after the prompt on the screen.
It was inconsistent enough I got _really_ good at typing my password, since it was normally quicker than waiting on the Apple Watch.
Contrast that with the Touch ID, that's always ready to go.