Wasteful by what standard? Right now each day it consumes ~$1m worth of electricity in order to protect ~$1.5 billion of new payments. Economically, this "electricity safety fee" works out to less than a tenth of a percent.
if you wanna compare it to all stored value instead (about $100bn), then the "electricity safety fee" comes out to ~0.001% per day.
(these comparisons are just meant to help put the electricity costs roughly in scale against the benefits they help provide)
[My initial calculation was wrong. It would have been 35% per year, which would have been more obviously incorrect!]
Ultimately we've reached a point where there are more efficient alternatives to having hundreds of people computing billions of hashes to reach consensus. To put this in perspective imagine a group of people sorting by randomly permuting and checking if it works, while stubbornly refusing to adopt near linear algorithms.
I suspect people underestimate the game theoretic consequences of stake systems like Algorand as compared to PoW. (For example, the dynamics of contentious forks may look quite different.) I don't know which is better! But those types of consequences are likely much larger (for better or worse) than the electricity savings.