Energy is one of the most important concern when it comes to mining. Eth is switching to PoS that will consume zero power as compared to PoW. In future those consensus algo will get huge attention that have zero power consumption.
Energy is main problem but this energy ensures the security and robustness of BTC blockchain. The other new consensus algos may have there own benefits but I dont think they have the capability to overthrow the PoS. Just my personal opinion.