Yeah why no global toggles for all features? What's the big deal with it? Isn't it obviously a good one?
Keep the defaults when GOS is just installed on the user friendly side for usability, but allow global toggles. Its such a waste of time to switch everything manually, specially good for "many users" setups.
I offer to also add "ask every time" permission level to all permissions, and apps including preinstalled ones, to keep them in control (at least to be more informed) - just speculating here
Arguments about increasing risks of breaking something doesn't sound intact with open source and privacy respecting mindset imo.