I used to worry about this question too. But how much energy has mining gold cost? Was it worth it? Will bitcoin have a similar impact? I imagine the answer is more, yes, and yes.
The premise of the OP is that bitcoin is not worth the cost. I tend to agree, though I can understand the appeal of decentralized currency.
https://www.coindesk.com/microscope-true-costs-gold-producti...
Except Bitcoin also creates electronic waste, including gold, and, I would argue, is not at the scale that gold is at, as an influencing factor on the economy.