What unrealistic promise did Apple make? I am curious when they said the app store is "completely secure" because obviously nothing can be completely secure.

I know they claim it is "the most secure" app store, which I am not sure what they use to back that up, it does seem to be one of the most secure platforms, it has my highest trust but I don't completely trust it.

As others have said I do believe a curated app is is more secure than an un curated one or no app store, but nothing is perfect and there is a trade off for that curation and tight control.