Oh goodness, where to start.
- It's not all about enhanced security (this is a nice extra), FaceID is primarily around high levels of convenience. You'd open your MacBook and it's unlocked. No positioning your finger for a brief moment which takes a couple of seconds to do.
- It is far, far easier to spoof TouchID than FaceID. Back when FaceID was released, yes there were issues, but Apple has mopped these issues up and FaceID is now more secure than ever.
- There has been zero evidence to prove that the FaceID "unlock with a mask" feature is any less secure. They've said it is less accurate (as seen in screenshots), but that doesn't mean it's less secure. If the result of an authentication can't be reliably determined, it won't authenticate. It just means you'll be likely to have fewer successful authentications, not more unsuccessful ones.
- Twins don't have identical fingerprints.
- FaceID is convenient as hell, that's why people are interested in seeing it in more devices.
- Apple Watch doesn't need bioauthentication at all, because you can use your iPhone to unlock it. Would be an overcomplication, make the device more expensive, and take up more space that could be afforded to things like battery (which is important on tiny devices like the Watch).
as far as convenience goes, it's debatable which one is better - personally, I find TouchID much quicker to use in real life & more flexible than FaceID (on a phone at least)...
- with TouchID, my finger is already unlocking the phone while pulling it out of my pocket and I'm already at the homescreen by the time I'm looking at it. with FaceID it's actually slower cuz the phone requires line of sight with my face first, and then I still have to swipe up to get to the homescreen.
- that also means FaceID is less convenient to use if your phone is laying on a surface that your face isn't hovering over at the time, whereas with TouchID you can just reach over and authenticate with your finger (and no swipe up, if unlocking!).
- I also prefer that TouchID is an action I have to explicitly carry out, since there are times when I may not want it to authenticate. this would also be true in situations while using a computer, so I'd also prefer TouchID over FaceID on Macs as well.
- another nice bonus with TouchID is the ability to register multiple users on the same device (for those that take advantage of this), since FaceID doesn't currently allow this.
- TouchID obviously has no problems with masks, glasses/sunglasses, hats, facial expressions, facial swelling (ha!), etc. (but in exchange, it can't be used with gloves though).
- not everybody wants to wear an Apple Watch
- FaceID is responsible for the atrocious notch - nothing is worth such hideousness.
I know a lot of people like FaceID & while it gets the job done, I just don't find it any better to use than TouchID and actually think it's arguably worse of an experience (to me)...