Any energy usage seems like a waste if you don't understand the benefits.
Bitcoins energy input is used to protect the monetary energy it contains from being stolen, by anyone. The value in the monetary units of fiat currencies is continuously being stolen through supply inflation which dilutes the same value across more units, halving the value every decade. This is what always happens when money is proof-of-work for most, but not for a select few who can create it effortlessly (the banking system).
Bitcoins energy input is used to protect the monetary energy it contains from being stolen, by anyone. The value in the monetary units of fiat currencies is continuously being stolen through supply inflation which dilutes the same value across more units, halving the value every decade. This is what always happens when money is proof-of-work for most, but not for a select few who can create it effortlessly (the banking system).
https://fred.stlouisfed.org/series/M2SL
What is money if it's not proof of work?