I'm pretty sure this doesn't actually happen on Android phones, and it doesn't even happen anymore in Windows, which runs with admin privileges by default. The toolbars and viruses were mostly a thing pre Windows XP SP2, and they were mostly gone with Windows Vista.
It does happen, but in a different form. Now we have programms that prompt us during installation to install another software (antivirus or browser [looking at you Ccleaner]) for no good reason and most users (including my friends and family) simply click next without reading anything. Same thing on Android but with sticker/gif apps. I can't keep track of the times I had to help a relative or friend with stupid fullscreen pop-ups or adds on their phone and with unwanted software on Windows.
I see it a good bit with less technical users on Android. They'll get apps which put full screen ads on their phone popping up all the time, they'll get ads on their lock screen, they'll get their default browser swapped out and not understand what happened, all kinds of things.
