Proof of work is the key innovation that secures the decentralized network. Thinking that something is possible with no energy is the real fantasy land of scammers (aka proof of stake)
Of course, there are ways the proof of work model is better too. There's tradeoffs both ways. But nothing offered by cryptocurrency makes up for the enormous energy usage of proof of work at scale, so the other consensus mechanisms are the only real, sustainable models for world-wide adoption