I do have a cell phone - it's just that it's what people came to call a "dumb" phone. No notifications barring an SMS or three a week from the bank. I turn off notifications by default unless it's something I'm waiting for (and that I know will come) while other stuff is under way. Sudden popups - especially those of miserable value - are annoying. I wonder how my experience is different from the mainstream - and what mainstream's is, for that matter.
The vast majority of those notifications are either neo-SMS (ie messages sent though Whatsapp or Facebook Messenger) or emails. I turned off all the rest. Oh, and calendar notifications, I guess, which I needed at first so I wouldn't miss class. Now that I've gotten used to my schedule I could probably turn those off too.