dBFT has solved the concensus mechanism without PoW for quite a while. https://docs.neo.org/docs/en-us/basic/technology/dbft.html#:~:text=Byzantine%20Fault%20To

dBFT has solved the concensus mechanism without PoW for quite a while. https://docs.neo.org/docs/en-us/basic/technology/dbft.html#:~:text=Byzantine%20Fault%20Tolerance%20mechanism%20is,Practical%20Byzantine%20Fault%20Tolerance)%20algorithm https://docs.neo.org/docs/en-us/basic/technology/dbft.html#:.... People talking about blockchain technologies being wasteful are just literally ignorant.