I think there is a consensus that maintaining the Bitcoin network is wasting too much energy, and such criticism comes often from people who don't have a hidden agenda and are well-disposed towards Bitcoin.
No, definitely not.
The energy is not 'wasted'. It is
needed to secure the whole network.
I don't understand why people think it wastes 'too much energy'. It is just a small small fraction of what the banking sector needs.
Also, how should the network be secured if the energy wouldn't be 'wasted' to secure it ?
Sure, we could easily shrink the energy consumption / hashrate to 1/10th of the current. But this would also mean that the network is 10 times less secured against an attacker.
And this also means that 10 confirmations then are worth as much as 1 confirmation is worth now..