Gambling is frequently banned because of its negative externalities. Are you sure this is the analogy you want to pick to defend bitcoin? You are correct that

Gambling is frequently banned because of its negative externalities. Are you sure this is the analogy you want to pick to defend bitcoin? You are correct that the ecological damage from bitcoin is only one of the things that makes it harmful. It happens to be my primary objection to proof-of-work cryptocurrency because I'm very worried about climate change, but I'm also not a huge fan of tax evasion or ransomware, either.