With all the great minds in the world, instead of fighting and complaining, why hasn't anybody come up with something better than Proof-of-Work to keep Bitcoin alive? Bitcoin is open source, if there is something that can keep the network secure without using all the energy, feel free to submit a bitcoin improvement proposal (BIP).
After all, if the world would agree and shutdown the Bitcoin network today, all the energy after all these years would "really" be wasted.