There is some interesting approach to AI-based NFT by Fetch.ai.
AI generates paints or drawings from user's input. And users vote on the resulting drawings. After a few rounds of this, final top drawings become NFTs and are sold in OpenSea.
AI generates NFTs and users vote on them, and then NFTs are sold in a market!
Fetch.ai is combining AI and Blockchain technologies, which will in my humble opinion be the future of AI systems.