I don't really hate NFTs but I'm very critical to (a) the way models of digital scarcity is introduced to digital artist by the blockchain (maximalist) tribes effectively making the whole thing very similar to pyramid schemes as you suggested, (b) carbon emission footprint of Proof of Work.

But to your question, I suppose any work in digital media which is fungible could be reluctantly considered as "polar opposite of an NFT". One could even do better than that and release the artworks under an open license like CC.