Biometrics can be hacked and can never be changed. These are NOT secure sign on solutions. You can be unconscious or a corpse and your device can still be hacked. Like your Social Security Number, if/when your biometric data gets leaked to the dark web there's nothing can do about it.

It's FAR more secure to simply use MFA that requires both something you know AND something you have. The something you have prevents online hacks and the something you know prevents physical hacking of your accounts.