Right, in some way, you need energy to run things. I like the 'battery charger' analogy.
There is also a lot to improve in the traditional economic system, but the direction seems to be blocked....

The crypto-currency trend is just getting started, and we still have the chance to do better than bitcoin before it generalizes.

In theory, every miner could validate a block within millisecond's, the PoW is only there to prevent fraud and randomize the node that will validate the blocks.

For example, look at this experiment what Google did to CAPTCHAS :
"....characters from Street View images are appearing in CAPTCHAs to improve Google Maps with useful information like business addresses and locations. Based on the data and results of these reCaptcha tests, we'll determine if using imagery might also be an effective way to further refine our tools for fighting machine and bot-related abuse online."

CAPTCHAS are not intrinsically very useful, but there is always room to improve.