Except implementing the functionality to optionally open up your device to the world inherently makes it less secure. I now have no ability to purchase the phone that I want. It's actually decreasing consumer choice.
If apple is incompetent and makes it less secure, I'm sure they'll fix it.
Are you saying that Qubes OS is less secure than iOS?
Recent versions of iOS have specific anti-jailbreak mechanisms (anti-downgrade mechanisms, ephemeral root filesystems) which don't provide general security, so they're sort of cheating. These mechanisms just mean it's harder to use the vulnerabilities for good, without significantly stymieing evil. (And they aren't wholly effective, seeing as 16.6.1 contains all of them, and it's still got a semi-untethered jailbreak.)