> Somebody is also going to inevitably leak it because security is difficult.
Phone numbers were and will always be assumed to be public. (Yellow pages are still a thing)
> unless I want to be less accessible to people who I may need to hear from.
You don't need to be less accessible to anyone. Your phone can and should be able to filter things for you.
And is not just a matter of setting up number filtering, I am talking about implementing changes in the application layer. One could imagine, e.g, a phone app that only rings if the caller provides a secret code provided by you, effectively making you reachable by phone number (public) + caller-specific code (private). You could also make that if you have the code on your addressbook, it sends it via DTMF after the call being completed.
> other than that the system cannot be repaired.
It can be repaired, it is just that the cost of these changes might be too high if mandated for all network operators.
But even if the system couldn't be repaired, the solution is not to encourage adoption of a proprietary solution. Apple already controls way too much stuff, we shouldn't give them yet another monopoly for them to exploit.