If we're talking about technical feasibility, then you're right, it's possible to compete with the app store with the web browser. However, the masses don't car

If we're talking about technical feasibility, then you're right, it's possible to compete with the app store with the web browser. However, the masses don't care about technology and protocols. It's about convenience and motivation. Any extra step will decrease adoption and engagement on the whole. All things being equal, if it takes any more energy to do something then, statistically, it will be done less.