You acknowledge that biometrics have some issues they don't solve. Not being easy to steal is one of them. The problem is that you leave your fingerprint all over the place, including all over your phone, there are likely multiple pictures of you publicly available that can be used to construct a model to fool Face ID etc. Most biometrics only provide really minimal security, and the ones that provide anything more don't provide much and are inconvenient.

I use my fingerprint to prevent people casually browsing my phone if I leave it on the table while I pee, but I wouldn't rely on it for more than that, and neither should other people.

You need something else (a key, password or something) to secure most things as well as just your fingerprint.