Apple's behavior is superfluous to marketplaces and your security. That's why they can promise security on macOS even though Steam is allowing users to buy and install games outside of the Mac app store. They even allow random unsigned software to be downloaded and installed without thwarting their security.

You pay extra for not being able to install apps outside of Apple Store?

Or more specifically, you pay extra so others couldn't do it on their phones (because you as I understand wouldn't, but you don't want others to be able to)?

Thats fine. They can have a locked-down by default setting that you can pay extra for. The rest of us would like an open store.

Arguing that the safety of the Apple App store is equivalent to that of the Google Play Store, or any of the other Android markets (which are far worse), is pretty nonsensical.

Numerous suggests you can still count them, which is an incalculable win against any other platform.