[httpsterio]

Can be and is the only sole option. Even if Apple's app store is baked in, I wouldn't balk at any commissions they feel comfortable with and any draconian rules they use to extort developers as long as users would have the possibility to install apps outside of the store, but as it's impossible (unless you jailbreak which can be more or less impossible on some devices) it creates a huge issue.

There's definitely benefits on being listed on the app store and developers should have the option to weigh the benefits against the cons to see if it makes sense to allow Apple to dictate their publishing methods and cuts they're taking vs self publishing, but that's currently not an option.