The proof-of-stake algorithms can disincentivize cheating within the blockchain, but I haven't seen any that have the type of external cost that PoW blockchains have. The fact that so many people are investing so much power in bitcoin vs. other currencies is likely much of what gives it so much value.
With proof of stake, what's the disincentive to participate in all forks, or even a large number of alternate histories. If there are multiple Ethereum blockchains using PoS, how can I as a new user determine which one is 'the' Ethereum?
Fast forward a few years ahead. Do you see more or fewer miners participating in such ecosystem?
PoW as it’s currently implemented encourages centralization.
Who's "we"? Because I don't. People who mine do. They do it by their own free will. It's their resources they spend.
If you want to talk about setting things on fire for no reason, let's talk about smoking. Google tells me more than a billion people smoke. I'll argue that the maintenance of a decentralized, publicly accounted money system is more useful than people inhaling tobacco smoke.
Ironically for the ether pumpers on this thread, the primary crypto currency that is powered by burning coal and oil is ethereum.
Forbes says "The largest share of the miners are located in China, close to the border with Tibet where cheap hydropower is relatively abundant."[1]
1.https://www.forbes.com/sites/peterdetwiler/2016/07/21/mining...
It's the global commons: carbon and other pollution from electricity generation, fossil fuel extraction. Manufacturing and building wind farms and solar arrays also have an environmental impact.