With the extremely low cost of power in China -the King of all Bitcoin mining-the efficiency of mining is still very real(for them). Then you have the growing mainstream acceptance of Bitcoin that no other crypto can even dream about yet. Have crypto and want to use a debit card like Bitpay? It's Bitcoin or nothing for most everyone. Shop on Overstock.com? Bitcoin.

A LOT of Proof-Of-Stake crypto are obviously nothing more than ponzi schemes and have no value except for short-term playing around. When you have a POS crypto that is paying a fixed interest rate , it relies on "new money" totally to pay it, not from any alleged business activities that they proclaim they might be doing. That's the downside of POS. Not having to be a slave to Antminer or rather medicore cloud mining companies is a huge plus for POS and strong argument against mining, even forgetting the energy costs.

When Ethereum goes to POS, it will be interesting. It's still profitable to mine until then and so are a few other crypto's with GPU rigs.