Any problem that an Apple fanboy points out with sideloading doesn't exist in real life.
"Apps will be out from the App Store and everyone will have their own store" not even Fortnite managed to do that on Android, people don't wanna download and create an account into a new store just to get one app.
"I'm afraid my nanny will download a malware ridden app from a shady website" this isn't a thing even on modern Windows, both Android and iOS are super closed that you can't do much harm to the OS without root/jailbreak.