What is the relationship between an NFT and its underlying asset? Or is an NFT just an arbitrary sequence of data stored on a blockchain?

I read an argument in the comments section for an article written on the economics subreddit about an NFT that declined in value from $2.9M to $3.6k and I was curious what is the rebuttal?

It's weird. He paid 2.9 million Dollars to buy a digital 'token' that 'represents' a series of words written and published on the internet years ago as a 'tweet'. Right. He doesn't own the rights to the tweet: anybody can read, repeat, print, speak or try to profit from it; he doesn't own anything about the tweet except a token that refers to its existence.

Its clear that nobody would pay 25 million dollars for a short series of words that are freely available to anyone - here they are: 'Just setting up my twttr'. No, that would be the height of stupidity. So why would anyone pay for or value a digital, arbitrarily assigned 'serial code' that refers to it? The words are not even contained in the NFT. Seems to me that NFTs have no intrinsic value to anyone.

This guy's argument seems simple and truthful and easy-to-understand but I'm aware those conditions alone can be misleading. Basically, I've never read a stronger "anti-NFT" argument on Reddit before in my life and I'm curious what's the rebuttal from someone who is pro-NFT?