Why not? Web browsers are not just for reading text based articles. Most use a calendar, email, perhaps some kind of chat app through their browser. Aren't these and other similar use cases good reasons for notifications to exist?
https://en.wikipedia.org/wiki/Inner-platform_effect
All in all, building out applications using cross-platform frameworks seems to be a far better solution for end users, and not significantly worse in terms of developer velocity, but I think there are other reasons they are not adopted, primarily that the web makes it far easier to invade privacy and deploy dark patterns, while that behavior typically is checked by the app store approval process for "native" or cross-platform applications.
Disagree. One reason sites want me to use their app is because I can’t block trackers. I wont use native apps if there is a web alternative BECAUSE i value privacy.