I can't believe people still don't see the obvious issue that PoW has no sense and it's impact gets progressively worse as the market cap of BTC increases. The more adoption BTC will have, the more incentive will powerful entities have to take part in mining (obvious analogy: US dollar, the people who control it have the most power in the global financial system). Also, the more valuable BTC becomes, the more new miners will join in the mining race, since the average payout per kWh spent should stay at a relatively constant % of market cap. Both of this observations lead to the clear conclusion that energy spent on useless hash cracking will continue to increase, which is just plain stupid. Humanity cannot afford to waste energy in such an obviously non-nonsensical way; if you want to keep the crypto train going, fine, but at the very least switch to PoS.