I believe you do not have to be an artist these days to sell an NFT, there are many other things that you could do. The question is "is there a way to earn from someone else's NFT" well in that case you can find one that is cheaper than what it should be, buy it, and sell it to someone else for higher amount of money. These days its very rare that you can buy an NFT and then sell it for higher which is proof that they are very expensive and highly overvalued, but if you can do that you could make a profit.

Secondly you could always work with an artist that is not aware of NFT or don't know how to, then cut him piece of the deal, give him %50 of the profits and then turn his art to NFT and sell it, if he can't do it himself than you should be able to do it for him and this way both of you would be earning some profit together, that seems like the only method.