It just seems arbitrary. I'd prefer we get rid of cows (14.5% global CO2) before we get rid of bitcoin. At least blockchains don't feel pain...
Cows are useful.
and can be used for food, unlike bitcoin which I can't even use to buy food. So much for being a currency.
For just about everyone, including almost certainly everyone reading this, cows are an indulgence that is unethical on many levels. For a relatively few subsistence farmers, cows are also useful.