Elephant in the room is payments. Was sad to not see this mentioned. Sure, building a web app might have a better chance of onboarding folks. But now try to get them to enter their credit card number. On mobile, they tap the "Buy" button.
That's fair. I do have something data about that, however. We tried making our app paid and found that we were now trading 100 free downloads for 2 at $0.99. So now we have 5% of 2 people instead of 100. Regular people are really price sensitive and the problem is they can find something that does something similar to what your app does for free. Like I said, they will not value their own privacy when making that decision, hence they will always choose the free version on mobile. I think in that future that will change, at least that's what we're betting on.