Whether or not most people are aware of this ability is another question, I guess.
But presumably developers have more control over app notification look & feel vs browser notifications?
The one that gets me is Uber. For several minutes a month while traveling, I really want their notifications. But once a day when I don't, they use it to send advertisements for services I can't even use (no Uber or Uber Eats service where I live). I used to turn off notifications the first ad I got after getting home (usually within a day), but then realized it's easier just to delete the app each time. And if Lyft hasn't advertised at me by the next time I'm traveling, and they're still installed, well, they're the ones getting my dollars, since who has time to download an app each use?
At least for now there are no ads there.