Hard to disagree currently, especially in the case of Bitcoin.
That said - and given that Bitcoin and many other cryptocurrencies were developed on the back of the 2008 financial crash as an alternative to the commercial banking system - I'm also quite sympathetic to the idea that Bitcoin is an example of good intentions with bad outcomes.
Kinda like the CFC chap: https://en.wikipedia.org/wiki/Thomas_Midgley_Jr.
Bitcoin is especially bad for energy consumption (see link below), and that cost is exacerbated by the insane amounts of hardware that miners use to keep up in the competition to mine the remaining Bitcoin as the price, difficulty and competition increases (it was once possible to mine Bitcoin on a low power CPU).
Not all crypto is the same though, and the more energy efficient currencies use less energy than Visa.