I’m not very familiar with dPoW but in principle I’m not a fan of being dependent on another PoW chain and it would delay finality further.
I’m not sure how PoS really risk to increase centralization in the case of #Monero. I think there is a case to be made for blockchain that had a premine but Monero supply is probably as decentralized as it can be. Plus, PoS would actually be fairer as it would lower the barrier to entry to compete for the block rewards (it’s easier to stake than to mine). Of course, we are likely to see the emergence of large pools but would that be any different than having large mining pools? I don’t think so, stakers can move from one pool another similarly to how hashers can. And in a hybrid PoW/PoS chain, the history of the blockchain is still guaranteed by PoW.
Really the only although critical benefit of PoW is to guarantee the integrity of the ledger without having to rely on a set of trusted validators. With PoW/PoS, when a new validator joins the network, it looks at the chain with the most work rather than rely on a set of trusted validators (for pure PoS chains).