Proof of Stake Computing Power?

Posted about this before but it got flagged as spam and deleted.

Simple question: If the network is currently burdened as-is, how will *reducing* the computing power by transitioning to proof-of-stake benefit the "global computer" that is the Ethereum network in the long run? Or is that not the goal for the network?

I know with Proof of Work, there's currently a lot of garbage bundled with meaningful computation to artificially inflate the workload as a distribution mechanism. Will removing that garbage and vacating all of that computing power still leave a powerful cloud computer in its place? Or will the network's total computing potential be hugely cut back without hundreds of thousands of GPU and teraflops committed to the task?

I guess it's a hybrid proof-of-stake, but the network without that garbage must still have steep computing demands, especially if it were to continue growing.