Another misconception about the App Store is that it makes apps secure and safe. It doesn’t.
There are things that do make apps safe. No matter how an iOS app is distributed, it runs in a sandbox. An app requires permission from the user to do things like access the address book or microphone. This is just how iOS works: it has nothing to do with the App Store.
The App Store review process probably does run some kind of automated check on the app to make sure it’s not using private APIs and doesn’t contain some kind of malware. However, this could be run as part of a notarization process — this doesn’t have to be tied to the App Store. (Mac apps outside of the Mac App Store go through a notarization process.)
Otherwise, App Store review is looking for basic functionality and making sure the app follows the guidelines.
As far as checking that an app doesn’t crash on launch — thanks? I guess? As for following the guidelines: the guidelines are about protecting Apple’s interests and not about consumers.
I would like to say that the App Store filters out bad behavior, but I don’t think it does. We’ve all seen various scam apps, and we’ve seen otherwise well-behaved apps do things like abuse the push notifications system.
It probably catches some egregious scams that we never hear about. I’ll apply the benefit of the doubt. But it didn’t catch that, for instance, Path was uploading the user’s address book. The community outside Apple catches these things, and Apple changes how iOS works so that these things can’t happen without user permission.
And, at the same time, the App Store is a magnet for scam apps. Even in a world where side-loading is possible, scam apps would stick to the App Store because that’s their best shot at getting users to stumble across them.
People have asked if I’d want my grandmother to download iOS apps outside the App Store. The answer is yes. That was how she downloaded her Mac apps, after all. (She was an avid Mac user.)
I’d feel secure knowing that the apps, just by virtue of being iOS apps, are sandboxed and have to ask for permissions. (I’m also imagining a Mac-like notarization step, for additional security. I think this is reasonable.)
In other words: Apple has done a very good job with iOS app security and safety. The fact that we think this has something to do with the App Store is a trick, though.
(I’m not arguing for getting rid of the App Store, by the way. I’m arguing for allowing an alternative.)