A proxy only routes traffic while the cpu cycles are happening elsewhere, allegedly, the data center that went offline.

Your argument only makes sense if those proxies are more than just routing network packets but also hosting the actual code of those bots. Oh, and you'd also need to assume there's no c&c, the bots should be autonomous. Else there's the single point of failure. If there's a c&c then they can all go offline with a strike.