The main problem of that failure is that people have used NFTs for the wrong purposes. The technology behind NFTs has many potential applications, and digital art is not the intended avenue and it does not even bring any benefits to that.
Who knows. The thing is that almost no one even tried to explore possible benefits. The vast majority of art-related NFT efforts assumed that throwing NFT on some random piece of of art will magically create something like ownership, fully ignoring that, no matter whether you're talking about fungible or non-fungible, a blockchain won't solve your counterparty risks.