One major scam that's lower effort here is that you can simply sell someone else's digital art. Selling physical art forgeries has always been a thing but the risks involved in doing it (i.e. what if you get caught) and the costs (faking a detailed painting isn't EASY) mean it's not as attractive as just grabbing some Japanese or Chinese artist's stuff off Pixiv and selling it as an NFT to english speakers, where the original artist may never find out about it.