It's more complex than that. Any alternative consumes large amounts of electricity unless you want to go back to the barter system so the "Carbon footprint" argument is overplayed and weak. Mining benefits everyone by giving actual value to the currency which would otherwise be worthless. Proof of work (mining) cryptos are the only cryptos that hold any real value because they require an input of real world value to be created. All others cryptos (and paper money for that matter) are merely speculation, speculation creates large bubbles and large bubbles get people reckd. Mining cryptos creates a store of value similar to mining gold or silver, the main difference being that gold and silver is tangible and useful for things other than value transfer while cryptos are designed to do just that, and they do it well.