Sure. They. They want. You know who they are, and what they want.
No need to play games and intentionally be obtuse all across the thread. "They" are the developers. A website has far less access to a device than an app and ads are easier to block. So they wrap anything into an app to gain that access and make ad money.
What marketer could turn this down?
https://apps.apple.com/us/app/loupe-what-apps-can-see/id6766...
Seconds since last reformat, number of times clipboard was used since last reformat, seconds since last reboot, dozens of other apps installed on the phone…
On Apple devices, so much is leaked to developers, and they will use it.
Loupe HN thread: https://news.ycombinator.com/item?id=48608645