Is that what's happening though? Are gamers grinding NFTs for whales, or something like that?
Err, no. People work for companies farming assets, xp and so on in a variety of games and then sell the accounts on the grey market. For normal games. In the NFT space Axie Infinity has a very similar model and similarly targets people in poorer countries with a pay to earn model although their currency was collapsing last I looked. Although it’s intentional rather than something games companies want to avoid it’s not actually mechanically that different.
gold farming is against the TOS and a bannable offense in many games though.
Yup, which doesn’t stop people doing it nor does it stop people doing it as a job.