It's because the apps work as black boxes stopping the end user from blocking their telemetry, advertising and tracking.
What I hate more is how companies deliberately add blocks to their websites if you're on mobile so as to force the user to download the app.
Two of the most egregious samples I've seen so far is Microsoft teams that shows a banner saying "this browser is not supported", but switching your user agent or enabling desktop mode from within your phone's browser makes it work perfectly fine.
Another is Facebook (yuck) which displays a fake loading bar that never finishes unless you trick it the same way as with teams. Their mobile site prevents you from posting anything, commenting, viewing random posts, uploading files, or seeing notifications. If you don't have the app installed, you're essentially locked out of messenger because it is reluctant at opening any shared files or posts as that has to be opened through the facebook app (obviously). What's worse is I'm prompted to log in to Facebook every time I open any link Facebook or not from within messenger.
I'd love to fully uninstall meta's apps but I have family members that only use their apps (fuck the networking effect)