Proof of Stake (PoS) is gaining momentum as a number of new protocols move to the PoS mode.  

Ethereum, the second largest asset by market cap, is expected to transition to this model within the next year.  A key benefit of PoS model is that it does not need substantial amounts of committed mining power making it more energy efficient than PoW.  In addition the ability of PoS coins and tokens to generate passive returns makes them attractive to a variety of investors and can incentivize long-term holding of the asset.