Funnily enough, people criticize Bitcoin's energy usage with them turning a blind eye on other "unnecessary"(not necessarily bad, but not necessarily needed for humanity to survive) energy hogs such as Christmas lights and gaming consoles.
What is the closest substitute to Christmas lights and gaming consoles? What is the electrical consumption of them? How much e-waste is produced as a result of them? What is the perceived utility of them? Is it fair to compare two completely different subjects? Shouldn't we be comparing it to the next best alternative?
There is both sides to a coin. Saying Bitcoin is a blatant waste of electricity is wrong, because PoW is meant to consume large amount of resources in exchange for the security of the chain. It is, however not wrong to argue that Bitcoin is a worse choice of payment medium as compared to Visa, Mastercard, SEPA, etc in terms of efficiency. Bitcoin's TPS is probably about 7-10 TPS, avg is about 3-4TPS in these few days and I daresay there is a larger proportion of transfers between services or exchanges than actual day-to-day use. Going by that, the efficiency of Bitcoin as a currency is far lower than that of it's closest substitute, by a ton. I think Visa alone processes 1,700 TPS probably at a far lower environmental degradation to Bitcoin.
The argument about Bitcoin's electricity wastage has nothing to do with the law of conservation of energy. Duh, electrical energy is primarily converted to heat energy. We're saying that there is a more efficient payment method than what we're currently having. 3TPS just doesn't cut it.