I went to a fingerprint-secured phone - just before I learned that someone had determined a way of duplicating a fingerprint well enough to fool a fingerprint sensor.
Facial recognition isn't what you see on TV (and especially not with a phone) - there are probably 100 people who could get your phone to unlock with their faces - and it's probably possible to get it to unlock using a picture of your face stretched around a dummy head.
Iris recognition? About the same thing (a picture of your eyes) and as you get older your eyes change, so you may not be able to unlock your own phone.
If the phone is in your possession, no one can open it. I never leave expensive things showing in the car and I never leave my phone lying around. (And I have a few fingerprints recorded and they all work so far. [I had an accident a little over 50 years ago that permanently changed one of my fingerprints, but a couple on each hand make it pretty safe.)