If your metric for success is simply how much money is being pumped through it, then in a sense NFTs are successful (although NFT prices and volume have been plummeting recently [0]).

However, I believe that the majority of people driving the popularity of NFTs fall into two overlapping camps: people who are simply trying to make money, and people who misunderstand or are otherwise oblivious to how the technology works and its limitations. To me it just seems more like a gold rush situation and does nothing to inspire confidence in the underlying technology.

Certainly there are people out there trying to leverage NFTs for more legitimate purposes - such as digital rights management and virtual items for video games - and those applications may be dubious enough by themselves. In the way they are generally being used, though, I wouldn't call NFTs a "success" any more than the South Sea Bubble was.

[0] https://en.cryptonomist.ch/2021/04/30/prices-nfts-dropping/