Yes, which seems reasonable to me. It would be more interesting if a global monetary system could use less than a bunch of casinos. (And maybe that will even happen with the adoption of proof-of-stake)
I don't have any of the calculations, but I would argue that we probably have one and it is the fiat global monetary system.
If bitcoin was a proof of stake and was the global monetary system I would have to re-think my opinions - at the moment it just seems like a cross between the worst aspects of Wall Street, the cookie clicker game, and the AI Paperclip Maximiser problem.
I would caution you to make your own judgements with such a hyped technology as cryptocurrencies. Everyone tends to have strong opinions about the way it "seems", both positive and negative.