I think that there is a place and a purpose for both Proof-of-Work *and* Proof-of-Stake models. For an uncensorable payments application, Bitcoin and Proof-of-Work is undeniably the answer. OTOH, to address the torrent of demand from blockchain applications developers who have use cases far less critical than sound money, Proof-of-Stake fits the bill. Blockstream’s Liquid idea of using federated sidechains to peg to Bitcoin’s settlement chain is interesting, and I think that non-critical apps that won’t have so much at stake as needing to withstand state-level attacks can benefit from the solutions coming out of the Proof-of-Stake space.