The moment a consumer-ready side channel is created, a few major brands will decide that delivering their app that way is better than conforming to Apple's rule

The moment a consumer-ready side channel is created, a few major brands will decide that delivering their app that way is better than conforming to Apple's rules and the whole security model comes crashing down. If it can be used by a major brand, some unscrupulous actor will gently guide my parents through whatever convoluted steps are required to enable it for their seemingly useful app loaded with badware. I'm glad there's no side channel.