I think we need to put this argument in terms of consent and actual harms caused. Human artists are generally down for other human artists to learn from their art and use their stuff as a reference for the purpose of learning, because the next artist generally will have their own style from their own quirks in muscle memory, skill, experience, etc. That contributes meaningfully to Art and keeps the field alive by allowing new artists to enter the field.

AI training is basically only extractive and has the potential to severely disrupt the actual field that made the AI systems possible at all. It's a much more mechanical process that the human interaction of studying a master. It doesn't develop any human skills.

Even if the processes were the same (and I don't think they are, as someone who has actually done computational psychology research), I would still think the AI companies are doing something they know is harmful to actual creative people that generate real value.