As much as I hate the App Store and want competition, for the sake of all the non tech loved ones in my life, I sincerely hope that either doesn’t happen, or that it is difficult enough to get people to “add” additional stores.
This doesn't seem to be the practice in a European country I live in btw, but I've seen it elsewhere (once bought a cheap android phone while travelling).
I'm not going to setup parental controls for Aunt Marge but sure as hell she'll call me when she installs spyware/malware and wants my help in fixing the problem.
I know that's the result of multiple app stores if a trusted entity can't/won't police them.