Things generally want to keep you engaged - and a native mobile app, even if otherwise functionally the same as a webpage, has somewhat more of a chance to get you to accept push notifications to spam you.
That, plus I think its to get you more invested. Like if you have the app on your phone you might want to use it again, or youll forget about it and then see it later and think about their product/service/whatever.
Things generally want to keep you engaged - and a native mobile app, even if otherwise functionally the same as a webpage, has somewhat more of a chance to get you to accept push notifications to spam you.
That, plus I think its to get you more invested. Like if you have the app on your phone you might want to use it again, or youll forget about it and then see it later and think about their product/service/whatever.