The environmental impact. And yes, I know, 0.5%, but my issue was always that if PoW currencies went from being a niche subculture to a point where it was used for everyday exchange (many people were arguing that this would and should happen) that 0.5% would surely go up by a great deal. To a point where crypto had to clear a super high bar of usefulness to counterbalance the harm it would do.
To be fair, AI training also has a big carbon footprint, but I feel like the utility provided by AI makes it easier to argue that its usefulness counterbalances its ecological harm.
To be fair, AI training also has a big carbon footprint, but I feel like the utility provided by AI makes it easier to argue that its usefulness counterbalances its ecological harm.