The biggest argument I've heard in support of side-loading and third-party app stores for iOS is:
I'm paying over $1,000 for my device. I should have the right to do whatever I want with it!
While I do agree with that sentiment, I firmly believe that would only lead to a shitty path for iOS. Marco Arment perfectly illustrates my my same sentiments:
I don’t expect side-loading or alternative app stores to become possible, and I’m relieved, because that is not a future I want for iOS.
When evaluating such ideas, I merely ask myself:
“What would Facebook do?”
Facebook owns four of the top ten apps in the world. If side-loading became possible, Facebook could remove Instagram, WhatsApp, the Facebook app, and Messenger from Apple’s App Store, requiring customers to install these extremely popular apps directly from Facebook via side-loading.
And everyone would.
Alternative app stores would be even worse. Rather than offering individual apps via side-loading, Facebook could offer just one:
The Facebook App Store.
Instagram, WhatsApp, the Facebook app, and Messenger could all be available exclusively there.
The majority of iOS users in the world would soon install it, and Facebook would start using leverage in other areas — apps’ social accounts, stats packages, app-install ads, ad-attribution requirements — to heavily incentivize (and likely strong-arm) a huge number of developers to offer their apps in the Facebook App Store, likely in addition to Apple’s.
Maybe I’d be required to add the Facebook SDK to my app in order to be in their store, which they would then use to surveil my users.
Maybe I’d need to buy app-install ads to show up in search there at all.
Maybe I’d need to pay Facebook to “promote” each app update to reach more than a tiny percentage of my existing customers.
This would be true for any conglomerate, including Amazon and Google. But I'm specifically concerned about Facebook.
We all know how much Zuckerberg hates Apple for implementing so many tracking-prevention measures that harms Facebook's business model. There's no doubt in my mind that Facebook would leverage its apps against Apple.