securing world's financial system is not a waste of energy; introducing any valuable side effects of mining would destabilize mining incentive system; energy is going green anyways.
Exactly. And mining using green energy is going to be the most profitable way to mine as the cost of solar drops. If we have a highly competitive / high tech mining industry, theyre going to be nimble to adapt to this change. Much faster than trying to convert the current banking industry over to green energy.
Plus people act like its trivial or easy to change the mining algorithm for bitcoin. Its never going to happen. It would lead to a contentious hard fork and market confusion because no way everyone would agree.