Whether Bitcoin uses less energy today than YouTube is immaterial. (As is whether Bitcoin counts as "sound money", which I'll leave to the side.) What's important is the energy use per transaction, the total of which -- if scaled up to match what's handled by traditional banking -- would be absolutely staggering.
My lifestyle of keeping my high-end PC running all the time, cranking the AC down to 68, turning all the lights on, and so on, would of course use less energy than YouTube. But if everyone behaved as I do it'd be a bad thing (don't tell Kant).
"If scaled up" presumes incorrectly that the costs are somehow linearly bound to the number of transactions, they are not, so that whole line of reasoning is flawed.
My lifestyle of keeping my high-end PC running all the time, cranking the AC down to 68, turning all the lights on, and so on, would of course use less energy than YouTube. But if everyone behaved as I do it'd be a bad thing (don't tell Kant).