@pre but that's for iOS. And it's in desperate need of regulation. Mandated sideloading can't come soon enough.
For Android, no single party has control over app distribution. Google Play is a *preferred* channel, sure, but no one's stopping you distributing self-updating apks from your own website or github or whatever.
@grishka Nobody's stopping you doing that but also more than 90% of people won't stray from the store.
I doubt anyone in my family other than me even knows fdroid is a thing.