I don't disagree that it's a depressing waste of existence to spend one's life keeping track of stuff. Especially if it's not even your stuff. But we've only had the computing power to take a load off us humans for a decade or two. And plus everyone needs a job (pointless or not) or the unemployment statistics start to freak people out. It's sort of the hand we've been dealt, the whole "let's work hard now for a better future we'll never see" thing.

I think the situation will improve dramatically when some of these crypto projects begin to mature. From what I can tell, blockchains are the opposite of lightweight, and personally I'm not holding my breath for one to become useful for anything besides profit anytime soon. I think something like IOTA is a better candidate to be useful (a fee-less directed acyclic graph, not a blockchain). It's more like a new communications protocol that will allow machines to conduct their own transactions with each other. The team's goal is to make it useful first, and if it's profitable too well that's great. Maybe I'm just not that creative anymore, but I can't see a production-quality future for blockchains, and would agree that giant PNW datacenters doing nothing but proof-of-work is a massive waste of resources.

That said, these are mostly just research projects hoping they have one of the big ideas that will win.