Late reply, but that is definitely "user error"; and the iPhone will exhibit the same problem if you allow any random app notifications access. There are plenty of bad actors, even on iOS. For example, even Uber Eats will target you with ads if you dare allow all permissions for notifications just to get orders tracking...

In fact, their notification system makes it complicated to just allow specific behavior and not something else. It's not better than the notification settings in typical web apps. As a day one user of iOS, I find it funny that you complain about notification out of all things, because if there is one place where iOS is just as fucked as every other platform it's notifications...

Nowadays I have resorted to basically denying notification for everything but the few stuff where they are actually relevant...

Also, you should correctly set things up for your mother and refuse notification prompt for every website and just whitelist the few that might be usefull..