I wonder how it is that we, as the users, allow it when iOS started allowing third-party. After that we accepted that macOS is more and more closed platform. And I'm hearing constantly something like "Yes, that's wrong, but at least platform is secure". For me security is less about how much platform is closed and more about how educated users are. On the side note that is interesting, that when first iOS version was…
One reason Apple was cautious about third party apps was the concern (from both Apple and carriers) that iPhone features would be misused or the iPhone itself might become unreliable or unusable. So when the App Store was rolled out the next year, apps required approval from Apple and were restricted to running in a sandboxed environment. (Background execution was also forbidden at first due to concerns relating to responsiveness, memory usage and battery drain, as well as security and privacy.)