I wouldn’t want that. If there was a switch on my phone where I disconnected from the AppStore and could side load what I wanted I wouldn’t switch it. I quite like the service the App Store provides for the apps themselves. But I just want them to charge a cut for apps.
Why not both? You get the AppStore and are allowed to sign apps for your own devices.
(We actually already have a workaround for this: https://altstore.io/ but it still requires Apple to sign your apps and is relatively difficult to use)
If you didn't want that, that's ok, but let the rest of us who want to do it, do it. I am perfectly happy with FDroid on Android and get a lot of my apps from there.