Comment by John Gruber

This, to me, is perhaps the key point that sideloading proponents ignore. Arguments in favor of allowing sideloading on iOS, from users, tend to boil down to “It’s my device, I should be allowed to install whatever I want. If most users want to stick with the App Store, that’s fine for them and they’ll keep all the benefits as they currently stand, while I and others will have the freedom to install whatever we want.” That argument is not wrong! There would be benefits to allowing sideloading, exactly along the lines of how there are benefits to being able to install apps outside the App Store via TestFlight, enterprise distribution, and compiling apps from source code with Xcode. [...] But many non-technical users would inevitably wind up installing undesirable apps via work/school requirements or trickery that they could not be required or tricked into installing today. Consider just the example of “proctoring apps” that students are required to install for remote test taking. They’re a surveillance menace, as the EFF reported in August. Technically, yes, on platforms that allow it, sideloading is the user’s choice. But socially and psychologically, it often isn’t. I’ll admit it: if Mac-style sideloading were added to iOS, I’d enable it, for the same reason I enable installing apps from outside the App Store on my Mac: I trust myself to only install trustworthy software. But it doesn’t make me a hypocrite to say that I think it would be worse for the platform as a whole. The iPhone is the converse: designed first and foremost for the non-savvy user, and tries to accommodate power users as best it can within the limits of that primary directive.