The only benefits I can see of "Apps", are the developer get's access to private information they really don't need.
Yeah, they get to be on the "App Store". But the "App Store" is a totally unnecessary concept introduced by Apple/Google so they could scrape a huge percentage in sales.
Web browsers have good (not perfect) sandboxing, costs no fees to "submit" and are accessible to everyone on every phone.
Not really. And this is why native apps are necessary. You can't use the built-in camera on an iphone successfully in this way, and I don't know any director who has. They use specialized third-party apps which give them the appropriate control.