I'm not a huge fan of bitcoin and have never owned more than 200 dollars worth, but that's a super weird argument to make.
Of course something only goes up in value if someone is willing to pay more for it, that's true of art, cars, houses, or whatever. You could argue that a house has more utilitarian value, as you could always live there, but that completely ignores the other persons goals. A house isn't going to be much value if jobs are scarce in that area, but bitcoin would still have value in that scenario.
All that energy is going to make sure you can send a large amount of value between two parties from almost anywhere in the globe with a minimum of transaction costs and a decent amount of anonymity.
This also ignores the fact of risk pricing. I live in Backwatermenistan and the political stability and the currency is looking unstable. I could buy a bitcoin from someone else who has one with local currency, I lower my risk of ruin from currency inflation by paying a price that I deem reasonable, the other guy gets cash which he could use to start a business or anything else that's inside his risk tolerance. No one lost in that scenario.