There should be an alternative App Store, plain and simple. As long as the sandbox for apps exist, users will be pretty safe. Apps should work the same way sandboxing works on PC browsers. Apple constricts Safari iOS because they don't want web apps to be fully competitive with native apps. E.g I prefer to use Overcast.fm over web than the native app, but most times, my podcast streams will stop abruptly in mobile safari, that i'm thinking of trading my privacy to Android for a pixel 1. Only thing that saves me, is I hardly use my phone, otherwise the limited functionality of iOS for devices you pay hundreds for is painful.