This has come up a number of times...probably because of the studies[1] over the last year or so. It's convenient to hit bitcoin on this front because it's conceivable to estimate its energy footprint. What I find frustrating is that we look at no other segment of tech this way. We never discuss the energy consumption of video games or the stock market. How can we say if this is very bad if we have nothing to compare it to? It's quite likely there are far worse offenders.
To be clear, I hold no bitcoin. I'm no fan of it, but I find criticism of its energy consumption disingenuous...especially when there are so many more valid criticisms of it to seize on.
[1] https://www.cell.com/joule/fulltext/S2542-4351(18)30177-6 and others