POS is a shit way of running your blockchain and it moves against the most important factor of a legitimate cryptocurrency and that is decentralization.  So where's that leave us? With POW.  The energy consumption is way overblown.  I'm not saying it's not an issues, but it's overblown and much of it has been debunked.  Also, you provide a bunch of conjecture here, instead of concrete facts to show that POW is truly moving towards a dead end.  I will take the word of cypherpunks and they largely agree POW is the best solution right now.