"What would _actually_ happen is a long list of companies would say "brilliant, we don't have to conform to the app store guidelines any more" and go sideload-exclusive"
This hasn't happened in Android, why do you think it would happen with Apple?
This hasn't happened in Android, why do you think it would happen with Apple?
Most importantly, Malware creators can just convince people to enable other sources. Most users don't understand the significance.