Curious if you're aware that mobile web usage dropped from 14% to 8% from 2014 to 2016[0]? And that according to Alex Russell[1], Google's internal telemetry has it well below 7% now. It seems to me that the opposite is true, that the irrelevance of the web on mobile will keep the web app versus mobile app division around essentially forever (web apps will be popular on desktop, and native apps on mobile). (Unless I was misunderstanding and you were saying, what's the difference? E.g., Facebook is Facebook, whether it's a web app or a native app.)
That's sort of proves my point. Many apps these days are just a web app with a launcher for your homescreen.
Lets say we have https://dynalist.io/. If you are going to open their web app in Safari and then open their iOS app - you will notice that UI is identical. Because it is the same UI! In one case you have to access it via a browser and the app is just the same frontend delivered to you as an iOS app.
PWA or something similar - is the future. Hence all those APIs in browsers.
I'm confident that soon enough there won't be such a devision as web app and mobile app anyway. That's why imo.