&gt; One you remove the need for PoW they are barely any more inefficient than a master-master DB with the combination of immutability and known entry ordering.<p>Once you remove the PoW - it&#x27;s no longer a blockchain. That is what a blockchain is. If you believe that blockchain&#x27;s don&#x27;t require PoW - then off the bat you have major security problems. But in addition to that - your definition of blockchains would mean that we&#x27;ve been using blockchains since the 80&#x27;s