[smoldesu]

> I just want all of my purchases and subscriptions to remain tied to my Apple ID and cancelable from my place.

That's what you get in a world with sideloading. The apps you've bought will remain on the App Store for as long as the developer extends agreements with Apple. If you don't sideload, your App Store purchases will be consolidated and organized however Apple chooses for you. You lose nothing.

The worst-case scenario for you is that your favorite developer stops using the App Store; but that's also a possibility regardless of sideloading. If a compelling alternative makes Apple's offerings seem weak, then it's up to Apple to respond.