[nfin]

Here something to read for those really interested in knowing both sides of the argument (PoW side in this case, as the potential benefits of PoS are clear to everyone):

https://medium.com/coinmonks/blockchain-myth-5-proof-of-work...

https://www.truthcoin.info/blog/pow-cheapest/

https://medium.com/coinmonks/proof-of-work-vs-proof-of-stake...

That's a bit to read, but not a topic that one should just think he knows about (and these articles have quite a lot of overlap)