Not to start a flamewar, but as a 35 year veteran, the permissions dialog is the same as what SELinux would give you. Apple are implementing an RBAC and require authentication and authorization on a per-app basis.

This is on top of their SEP and read only System volumes with secure boot. Leave aside the argument about system openness to modification, that is beyond Unix's security and permissions model.

Sure, Unix offers some of that with chmod and mount options, but it's hardly a comprehensive solution.