I think you should go back and read it again, it says that a NFT is a "pointer" stored on the blockchain, basically a URL, that is not a representation of anything. That is a direction to something and that something can not be verified to be a specific thing. If you buy monkey.jpeg that shows a gorilla, when using your phone. It's not none fungible or unique if shows a donkey when using your computer to follow the url/pointer/direction.
So please enlighten me with how that a None Fungible Token of an URL can have a value, to me it reads like its very not "none fungible".
How is the guy who did the writeup I linked to, being dumb? He pointed out problems with NFT as he saw them and he broke the premiss of the system. From what I read, he did the equivalent of creating collisions in a hashing algorithm, basically said that it does not work as intended.
As for NFT being a good investment, any ponzi scheme is if you get in the ground floor, except for the possible criminal liability you run.
Do I wish I had not sold my bitcoins at 1000 USD, hell yes, do I wish I got into the NFT world early and earned a gazillion bucks, sure, who does not like money.
But it does not make it the best thing since sliced bread.