For anyone in the US you do need an ID to use Bitcoin in any practical manner. Exchanges require it. Avoiding this requires jumping through multiple hoops, especially if you want to convert to cash.
People don’t think about the environmental consequences because most people don’t think about that anyways. We’re also on HN, where software companies use or rent computational power with zero regard to the environmental impact. And for Bitcoin owners it’s specifically in their financial interest not to think about how Bitcoin miners are using more electricity than actual countries.
All of that said, Bitcoin is a failed experiment. People aren’t using it as an actual currency, they’re hoarding it. Partly because of the model and mostly because trying to actually spend Bitcoin sucks badly.
Bitcoin is going to be replaced by a cryptocurrency that’s actually usable and competitive with existing payment networks. And hopefully one that doesn’t use such an electricity intensive model.