Yes, I want to do that, but Apple, Microsoft, and Google (as Android) continues to veto that. And there are some arguments for why (the advantages of the walled gardens of the "curated" platform stores, the tech inertia of the different APIs of apps vs websites, and the learned user behavior).

Mozilla tried "Firefox OS" and it's hard to do it. Chrome tried service workers and persistent sites/apps, but.. it's just lame compared to shipping a separate app that bundles a web view and a backend.