Didn't Epic get some kind of magic injunction saying that Google had to allow open access to the entire Play Store catalogue or something?
Not that it requires Google to "open up" their play-store, but that they must allow other app-stores to work on the same level. So basically allowing devs and users to move elsewhere.
Apple moved first with making a special 'sideloading' case for apps not under their control, Google is just copying what they did.
No more free sideloading.