This person sounds like a future manager in the making. I've dealt with them in the past. If you're lucky, they'll somehow manage to find a better paying job elsewhere. More likely though is that if you want to get away from them you'll need to find a better paying job elsewhere, or change teams if possible.
To a certain extent, dealing with incompetent/adversarial colleagues can be a learning experience. You get better at designing/coding/communicating in a more idiot-proof fashion. But after a while it starts to hold you back as instead of being able grow, you instead have to stay behind and clean up after the others.
I would say in some cases, people are conditioned now to expect an app, even if it's basically a website. I think in a mobile context, most non-techy people don't normally think to open up a browser and say, browse Amazon or something. Instead they go for the Amazon app on their phone, and browse/shop/whatever there.
I wouldn't say this is exclusive to phones either. I once worked on a product that was essentially web-native, but they had to ship a desktop app because their market expected it, even though it was only a web-view wrapper to the website. No offline storage, no difference in behaviour, or need for some specific API; nothing. I guess you try explaining to boomers that a web-view desktop app is unnecessary.
The data vacuuming and additional marketing are just added benefits for the app developer, if they go down that path (they usually do).