In reality, it's going to screw so much stuff up and do so many things you don't want it to do, that you're going end up spending a lot of time just correcting all the mistakes it makes.
And when you're not fighting to stop it from doing more things you don't want it to do, you're going spend your time worrying about what it will do next that you're going have to fix.
And unless you pay for the most expensive phone and the most expensive tier of service, they'll probably dumb it down on purpose and your life is going be hard.
It's not just facial recognition anymore, though, they're looking at all kinds of other stuff, even how you walk.