Web notifications are one of the worst things to happen to the modern web. Ever look at your grandma's Samsung phone? She's probably got 5 spam ads saying you won a contest or to claim some offer. Most users are conditioned to just accept whatever popups are shoved in their faces, ESPECIALLY since the EU laws a few years ago that forced every website to tell about their cookies policy. And hell, I've accidentally accepted push notifications from sites throwing a popup in front of me while I was trying to click something else or scroll.

Apple was completely right to not allow web push notifications on iOS. They're 99% abuse. I don't even like them on desktop either.