Sandbox escapes are incredibly common, Apple still controls eliminating your business from iphones if you attempt to use an exploit to pull user data when you distribute through the App Store.
If you can do distribution via your own site, it becomes a whack-a-mole game with Apple - where data exfiltration exploits are found, Apple fixes them in a new update, then we have to wait for people to update.
And until most users update, the at-fault company is busy siphoning data from any user who can't update (e.g. no wifi / limited data plan) or any user who is slow to approve the update dialog. Eventually the company's app will grow to contain an exploit for the last dozen iOS versions that conditionally execute based on the iOS version/feature detection/probing for exploit availability.