Probably doesn’t have auto defrag because God forbid the OS do anything useful for you without a hundred terminal commands and a two hour setup lest all the sweaty arch users barge in with claims of bloat and “reeeeee why can’t I just decide for myself”.
But here’s the thing - side loading, even on android, is an opt-in feature. The user has to actively go out of their way to sideload an app. Even if an app tries to do it behind your back, you must first enable its ability to do so.
Yes, this doesn’t exist when ADB is involved, but in that case you have to go out of your way to enable USB debugging (and be stupid enough to plug your phone into someone else’s computer). The vast majority of iPhones will never have sideloading enabled by their users. The EU isn’t grabbing their balls and saying that all users must have it enabled by default, otherwise they’d be going after Android too.