The California case this appeal is all about said otherwise:
"Thus, the Court finds that centralized distribution through the App Store
increases security in the “narrow” sense, primarily by thwarting social engineering attacks."
"Since then, security and privacy have remained a competitive differentiator for Apple. Mr. Cook testified that privacy is “a very key factor, one of the top factors who people choose Apple.” The documents bear this out: internal surveys show that
security and privacy was an important aspect of an iPhone purchasing decision for 50% to 62% of users in most countries— and over 70% in India and Brazil—and an important part of an iPad purchasing decision for 76% to 89% of users. Indeed,
Mr. Sweeney himself owns an iPhone in part because of its better security and privacy than Android.
Second, there is evidence that Apple’s restrictions benefit users. As noted above, many users value their iOS devices for their privacy and security. As the result of having a trusted app environment, users make greater use of their devices, including by storing sensitive data and downloading new apps. The witnesses are unanimous that user security and privacy are valid procompetitive justifications."
Case 4:20-cv-05640-YGR Document 812 Filed 09/10/21
I find it interesting that no one who wants force Apple into side loading wants to address this part of the court's ruling.