Eh. Nah, probably not. Proof-of-work energy waste with cryptocurrencies is a problem specifically because of its scale, and the relative worthlessness of the activity.
Human basal metabolic rate is around 100W. Actual energy use per capita averages up to 10,000W, depending on how wealthy and boreal you are. If you want to count "energy waste", a successful DDOS costs each blocked user multiple hours, at multiple kilowatts.
It's no more a waste of energy than using advanced video encodings, or running `bcrypt` on passwords. The energy cost is comparatively miniscule, and it solves or mitigates other problems.
Human basal metabolic rate is around 100W. Actual energy use per capita averages up to 10,000W, depending on how wealthy and boreal you are. If you want to count "energy waste", a successful DDOS costs each blocked user multiple hours, at multiple kilowatts.
It's no more a waste of energy than using advanced video encodings, or running `bcrypt` on passwords. The energy cost is comparatively miniscule, and it solves or mitigates other problems.