Is Proof of Work is going to lose popularity compared to Proof of Stake? Ethereum is going to PoS. 
Is there going to be a lot of hash (computational) power idle because of shifting to PoS?
Where that power be used then? Will it address such decentralized computing projects as Golem, Storj, Sia, etc?
Is there going to be a lot of hash (computational) power idle because of shifting to PoS?
Where that power be used then? Will it address such decentralized computing projects as Golem, Storj, Sia, etc?
POW will not lose its popularity for the reason that it has a distinct advantage over POS. Other coins are shifting to POS for some reason, probably to attract more investors because in POS, you can have profit by simply holding your token since it will generate new token unlike POW. And I think those machine that mined ETH will be pointed to other profitbale POW coins.