We're straying a bit from the original topic of direct access to hardware, but I'll humor you. Let's look at one of your users who does click yes to everything. In $YEAR, spam websites will say "enable push notifications to view this funny cat image. In $YEAR+1, spam websites will say "install our PWA to view this funny cat image" or "install our native app to view this funny cat image" and our user will still obey because the popup is in the way.

For the clueless user, nothing has changed other than which button they obediently push. For the savvy user, you've added an arbitrary special case and a hoop to jump through to get the functionality you wanted in the first place. Neither case is improved in the end.