The funny thing is, Apple originally had plans for sideloading all the way back in 2008. An email that came out from the Apple vs. Epic trial last year had none other than Steve Jobs signing off on UI copy for installing apps from outside the App Store! [1]

Obviously, those plans were shelved when they changed strategy for iOS to walled-garden, but it's surprising how in the course of fourteen years the issue went from product roadmap to cultural anathema at Apple.

[1] https://www.theverge.com/c/22611236/epic-v-apple-emails-proj...