I can only speak to the Mac situation, but most people there would not have "root" in the traditional sense:
* Pedantically speaking, you can not even log in as root, any root level access would have to go through sudo (which is indeed enabled for most users).
* But additionally, even as root, Macs by default have System Integrity Protection enabled, which makes most system files non-modifiable. Users still have full control in that they CAN disable System Integrity Protection, but that involves a reboot and some (documented) command line commands, so most users don't bother doing that.
Literally 0 here, have you really?
Like I literally do not know anyone who is even using Linux to begin with but also people do have “root” in their Windows and MacOS systems. I do not see anyone destroying their computers at random.
Also to steal someone’s information you don’t need root access or any administrative access - if you already tricked the user into running your code then you can steal their passwords or whatever, all of that is user-level data.