Have you ever had your phone searched by the police or at the border? I haven't, but I have had someone try to unlock my phone before.

I'd contend most people have a threat model that puts opportunistic access by household members or someone watching them enter their passcode and then snatching the phone and running above border patrol search.

While you can't change your biometrics, walk me through why that matters. I'm not sharing my biometrics outside of the device, and you can't submit them remotely, so if you lift a print off of something it doesn't really get you much without also taking the phone. Once you're there, you're a bit beyond the typical phone thief in terms of threat.

The most common vulnerability is having an absurdly weak password, pin or unlock pattern. For those people biometrics is a vast improvement specifically because it's both secure against likely threats, and it's just as easy as hitting 5 four times in a row.

Every method has trade offs, and there's nothing to gain by pretending otherwise. Likewise, I don't think I would ever say "never use something", except for some contrived examples.