This system has obvious flaws, the first of which that comes to mind is how someone would respond to true catastrophes like a site going down for other business

This system has obvious flaws, the first of which that comes to mind is how someone would respond to true catastrophes like a site going down for other businesses which are mission critical or represent critical infrastructure. But... what if this was a rule that only 10% of employees could be 'on call' at any given time. This could result in more independent contractors which probably isn't positive, but what are the other benefits and detractors of a system like that?