Lol. If phones were actually considered critical devices like this implies Android would have been nuked from orbit.
No. They're computers with a modem peripheral. This is like saying once you plugged your e machine into the phone line it could interfere with 911 calls so they need to be regulated by the FCC. We settled that one over 50 years ago.
Besides the FDA (and similar international counterparts), you're also using your phone for a bunch of other stuff that you probably don't want anyone having root access to.
Wallets are one, banking apps, medical data and devices, password managers, and more.
If you have root access, that means that the apps can also get it, after all the app providing root access is itself an app.
Yes I have my bitcoin-qt wallet, Etrade, my ssh keys, and my password manager on a machine I also have root on. I don't run non-free code on it (and I'm very picky about the open source code I do run.) Also just because I have root access doesn't mean I'm running all my apps as root. That's in insane statement to make. I run administrative tools as root and that's it.
The same thing is happening on your phone, you're just not allowed access to those tools, instead various other companies are and when they do things you don't like your options are: throw out your device and data, or bend over and take it.
Again at the end of the day a computer is a computer regardless of you being administratively locked out of yours.
No. They're computers with a modem peripheral. This is like saying once you plugged your e machine into the phone line it could interfere with 911 calls so they need to be regulated by the FCC. We settled that one over 50 years ago.