It matters who you're stealing from. And if you're undermining the system itself. This is why counterfeiting currency is considered such a serious crime. If I photocopy a $1 bill, I get, what, $1 for free? That's not that big a deal. But because having fake currency in circulation undermines the entire system, and thus makes for serious crime, so, too, does having fake listeners and getting rich of the royalties. Who cares if Spotify's CEO can't get buy forest in Sweden, in duping the system, it undermines the drive for real actual human people to create music that other actual human people want to listen to. That there are other injustices on the world doesn't undermine this injustice being addressed.

I simply don't buy that this is like copying a $1 bill.

And I don't think you do either. I think one could construct a suitably objective test that would relegate certain instances of this sort of fraud to the civil courts where I think they belong.

Part of the problem is conflating the private Spotify ecosystem with "the system" writ large. In any event, a civil case with appropriate punishment would serve to dissuade others from taking the same action.

What does adding a prison sentence accomplish?