It's the same with artwork - people will buy anything, so long as they feel it has value.
I just watched a video about how hedge fund companies are trying to make video games as the next big investment asset, since it's highly unregulated and you can create artificial valuations that are difficult to combat.
For example, they took old SNES and PS games and are having "third-party" graders rate it as highly valuable (they own the graders) and then putting it back on the market and selling these physical copies of old games for like $1.5 million dollars.
What people don't know is that they're selling it, and buying it from themselves every few years - and keep doing that to artificially inflate the price - but it makes it seem like there's a huge market and continued valuation for it, when in reality it's just the buyer inflating the price.
Artwork, coins and NFT seems a lot like this. Inflated value that's hard to criticize because art and the concept of value are subjective, but gold has a fixed price based on what people will actively trade for it.