When you buy NFT, you don’t actually buy ART, you buy a verifiable unhackable proof of ownership.
Yes, you can download most of that art for free, but so can you torrent apps and movies, but you don’t do that, do you?
Placing NFT on a blockchain requires processing. There’s a fee. BUT, it goes to a random miner, not the marketplace. They don’t earn from it!
And there’s a good chance neither would you!
NFT’s are not about quick profit, it’s about POSSIBILITIES!