This is it. And it's really the app stores that make them so.
On desktop, people are wary about installing programs, because they can pretty much do anything. So you can get people to visit your website who would never in a million years install your app on their PC.
With app stores, people assume that apps are safe, because that's what they were promised. But then the apps are hoovering up all their personal information, even more than they get from a web page on a desktop. And the app stores that claim to be constraining bad behavior don't kick them out for it because huge social networks are some of the few companies with enough market power to divert their users to another phone platform.
While mobile apps are quite awful from this perspective, you must consider that the web is by far the most efficient platform for ad delivery and tracking.
It's the web which has cookie pop-ups with dozens and dozens of companies that want to track you.
It's the web which led to the development of ad blockers.
It's the web where an app developer has full access to your data on their servers.
It's the web where an app developer can at any time flip a switch and turn on telemetry, ads, etc.
In native apps, you mean?
There is a good reason why so many websites push you to use the apps on mobile.
[0] https://f-droid.org/de/packages/net.kollnig.missioncontrol.f...
[1] https://f-droid.org/de/packages/nya.kitsunyan.foxydroid/
Harder to track people and feed them ads.