Apple will make it annoying enough to sideload that no meaningful amount of users will do it, causing it to be largely irrelevant.

It’s only worth it to app makers to have side loading if they can do it for large numbers of users, bypass the app store’s rules, and bypass apple’s take. I’m expecting apple to set it up in a way they can do none of those things, by making it cumbersome to sideload, not giving entitlements to apps not published through the store, and by taking a cut for sales from sideloaded apps.