Uninstall enough apps and you’ll see the crap left around.

And yes, MSI is mature compared to Android, by a country mile (as much as it sucks. I’ve done app packaging since the mid-90’s, before MSI, and what a massive difference it made). Even with it’s challenges that are largely a result of having a no-rules OS at first, just like Android, it very rarely has issues today, and then usually just for trying to do things that are work-around for apps that don’t want to follow guidelines (very few of them anymore, 99% of the time I can just run through setup and let it build the difference file). Most apps today take a matter of hours, including full testing, when they used to take days.

In theory Android has a cleaner app install/uninstall process (it’s really good, and getting better), but it still leaves stuff around sometimes. I’ve seen it plenty. I’m not sure why it happens, I just know what I see. App data folders left behind, downloaded files left behind (even with scope, because the download folder is still used).

Just because the latest versions of Android have scoped storage doesn’t mean that there isn’t crap spread around. Having reset many phones I’ve seen the difference between just uninstalling all your apps and wiping the partition.

I have folders all over the place that no uninstall will touch. My download folder is currently 8gb, and no app uninstall will clean that.

I have a half dozen folders from apps that are no longer on my phone. One has a file in it dating from over a year ago…I remember testing the app then, and uninstalling it.

Just yesterday I reinstalled an app and expected to have to create a new user account for it, but it found it’s old data folder from when I uninstalled it in August.