[breser]

At least on iPhones though they have a way to activate a mode that prevents the use of TouchID and FaceID. If I press the power button on my phone 5 times in a row that turns that off.

Yes I still run the risk of my device being unlocked against my will if I'm caught by surprise. But I'm able to disable this functionality in places where I think the risk of that may be higher, e.g. while traveling.

I'll still take the trade off of longer password (not just a few numbers) on my phone while using a biometric test for normal access.

Of course not everyone may have the same threats to consider and others may make different choices. Doesn't make either of our choices wrong.

[kurthr]

On modern FaceID phones you need to hold the power and down volume key to bring up the Reset/PowerOff and cancel. Just clicking multiple times will bring up wallet, siri, or do nothing.

[PhantomGremlin]

Just clicking multiple times will bring up wallet, siri, or do nothing.

On my iPhone 13, just now, I rapidly clicked the power button 5x.

The phone immediately made a loud sound and put up a screen that said "Emergency SOS". There was an option to "cancel" it, but I assume that the phone would have contacted 911 in short order unless I quickly cancelled.

So the correct description is probably "it depends".

[Elidrake24]

Just hit the power button 5 times on my iPhone 13 Pro, and it locked down FaceID as I'd expect (while bringing up the Reset/Power Off screen). You've described an alternative method, not the only.