BTC for many is a way to stop central banks from eroding their lifetime savings which they paid for with their physical labor and time. Thats not a waste of energy in my opinion.
The narrative about central banks eroding life savings is greatly exaggerated by people who want us all to buy Bitcoin. Inflation raises the price of assets in general (virtually the definition of inflation), meaning virtually any non-cash investment will be buoyed by inflation. The idea that Bitcoin is the only way (or even a particular good way) to avoid inflation is a myth.
Source for this?
Buying into a token pool hoping you will be able to resell it for a bigger piece to people who want to enter as well is not something people should do in general.
BTC is terrible as currency fit many reasons. It has an advantage of skipping over regulations transactions in other currencies are subject to. How long it lasts is a speculation game. You can win at it but it's anything but "stopping central banks from eroding savings".