> PoS is closed-membership with a veneer of open-membership, because the means of coin production are tied to owning a coin already. What this means in practice is that no rational coin-owner is going to sell you coins at a fast enough rate that you'll be able to increase your means of coin production
It seems to me like they're arguing that PoW is more egalitarian/decentralized, which may be a fair point. But using the same argument, attackers being forced to buy stake in the open market should make PoS even more secure against 51% attacks than PoW.
Why would they need to buy 51% stake? Just buy x% and then knock the remaining staking nodes offline so that less than 2x% stake remains participating. That's often much cheaper.
It seems to me like they're arguing that PoW is more egalitarian/decentralized, which may be a fair point. But using the same argument, attackers being forced to buy stake in the open market should make PoS even more secure against 51% attacks than PoW.
I think this is a good post explaining the tradeoffs: https://vitalik.ca/general/2020/11/06/pos2020.html