Apple has just engineered the worst possible situation for themselves by being the only way to get apps on the store and by simultaneously incessantly marketing the store as "Safe and Secure". The former encourages them to maximize the number of apps on the store, while the latter encourages them to shoot first and ask questions later. If side-loading or alternative ways of getting apps onto the iPhone existed, then…
Instead, I’d like to see Apple be forced to provide bootloader unlocks and some basic drivers for alternative operating systems. We own the hardware, after all. Then they could have their walled garden and people who wanted more could run something else.
It’s also a simpler and more generalizable goal, in my opinion. If you own it, you should have low level access. That sounds more reasonable than forcing a corporation to add open App Store access, maintain it, and deal with whatever market effects precipitate.