My argument is that it should be the only step that is fair for both sides, efficient to implement, collapses bureaucratic policy to single sentence, doesn't create "issue created here - must be solved somewhere else" problems, nourishes progress, gives true freedom to purchased item owners, preserves good capitalistic incentives and many more.

Sideloading will be full of complicated very important details sucking out live from all parties involved.

I think we all agree that it should not be possible to unintentionally click or autoload link that downloads some settings app that looks like ie. iOS settings app but is developed by some shady party that has access to ie. your biometric security primitives, can look like/impersonate any built-in app/OS behavior etc.