I think this begins the search for another trustless transaction system that is neither PoW nor PoS.
Why can't these hypothetical powerful people rent time on a mining farm?
PoW is PoS, it just has some extra steps that have the minor side effect of using huge amount of resources for no reason.
They can, but so can the rest of us. Unlike under PoS.
This argument is straining so hard to find a way in which these two things are different but PoS and PoW are absolutely the same thing, just one of them is cheaper, more decentralized, and cleaner. PoW doesn't imply greater decentralization, in fact it implies the opposite. I can go build a $100 computer right now, load it up with 32 ETH, and begin validating transactions in minutes. I am on an even footing with every other participant investing a similar level of resources. If I want to mine some PoW BTC, for example, i first need the industry alliances to get the latest greatest mining ASICs (which are mostly not available, because the manufacturers are strongly incentivized to use them for themselves and a small group of allies) or I had to get a team of engineers to design one and contract a custom silicon foundry to produce one, wait a year or two, and then plug in my new miners with an enormous capital investment.
It sure seems like one of these is more decentralized, and I don't think it's the one you want it to be.
It's also wasting by actively destroying storage disks.