Well never say never but doing this would completely destroy the ability to build software on a mac.

I don't understand this comment. Apple has will for many things. They could give you a rubber room to build software on a mac or even an ipad, but keep strings attached and not let you run it without asking permission (like ios now)

iOS security is good for consumption use cases.

Developers need flexibility, e.g. VMs isolated by Apple Silicon nested virtualization.

and "consumers" could continue, while more creative types (the crazy ones) could have a way to allow a few of their own binaries to run in the way they want.