The Pixel 4 series only uses face unlock for biometric authentication; it is that secure. Or is it? Well, a video of one device unlocking to closed eyes suggests otherwise, as does the possibility of someone who merely looks "a lot like you" authenticating payments with your face data. Is the face unlock on the Pixel 4 series not so secure after all?
https://www.notebookcheck.net/Google-warns-that-the-Pixel-4-can-be-unlocked-with-your-eyes-closed-perhaps-even-by-someone-who-just-looks-like-you-too.439524.0.html