The jargon surrounding all this is just horrible and leads to confusion. There is almost nothing new here. In short, NFTs are just a new way of owning things.
1) People want to buy/own things
2) People want documentation/proof that they own things
3) People want to sell/dis-own things
What has changed?
1) Someone invented this thing called a blockchain which is just a database
2) Someone else invented a way to store contracts in this new database
3) People started wanting to buy digital things
2) Nothing else really
Lets start with something fairly straight forward. Most people here will have a property/home that they bought that has value. Today, there is generally documentation (a deed) that is recorded with the County office that "proves" you own your property. I assume most people here are happy with this concept. What if - instead of storing the deed to your house at the county office, it was stored on this new blockchain database? Nothing would really change. You would still own the house. If there was ever a dispute, all the police officers and lawyers could still access the deed on the blockchain. This would be considered a NFT for a physical asset. Only difference is where the contract/deed is stored. Ohh - and if we did this there would be no County fees for registering the deed. There are many assets for which there is no registry at all, but maybe there should be. Currently there is a registry for cars, but none for lawnmowers. The blockchain can be a registry for anything.
For the second example, lets take something a bit more wishy washy - baseball cards. What exactly is it? It is a small piece of cardboard with a baseball player picture printed on it. With today's technology, you could make a 100% exact replica of one. You can also look at every baseball card online if you want - and it would probably look better than whatever card you own. But still, many people think they are valuable because some of them are rare. Note the rarity was artificially made by the company who issued the cards. But if you do buy a Mickey Mantle rookie card for $2+ million, all you get is to carry around is a small piece of cardboard. You do not own Mickey Mantle, you do not get any rights to use Mickey Mantle's name in a business, you do not have any rights to the TOPPS name, you can not really do anything with the fact that you own something with Mickey Mantle on it - except sell it later. You can pull it out anytime you like and gush at the fact you own it. You can show it to your friends and hope they gush. I do agree that a baseball card is physical, but still it is just cardboard with a picture which should be worthless except it is not. If you did buy one of these, there is currently no registry where it would be recorded. You would need to always provide documentation (provenance) to prospective buyer to prove it is original and that you own it. Maybe it would be good to have a registry and this new blockchain database can do that. It could do it for anything really. If we stored the ownership for this card on the blockchain then we would have another NFT for a physical asset.
And now we get to where we are today. Digital stuff. No one would argue that Picasso makes weird art. It is skilled and took him a long time and his art is valuable. Beeple makes digital art that is weird and takes him a long time. Some people think it is valuable so he sells them. Let's say Beeple sold you one. He would give you a URL to a jpg file, plus he would give you a physical signed contract (rolled up in a bow) giving you exclusive ownership. Would this be acceptable? Would this not be just like a baseball card? True that anyone could look at it anytime. True that anyone could copy it anytime. But I can go printout a Mickey Mantle card right now and no one would think I own it (I dont have provenance). And if I tried to sell it, I would be busted for fraud. Now what if Mr. Beeple doesn't issue a paper contract, but instead stores it on the Blockchain. Now I have NFT that proves ownership of a digital asset. Anyone else could say they own it, but we could check the blockchain and prove who does.
In my opinion, the confusion craziness surrounding NFTs is more about the value being assigned to digital assets. I do not think a Mickey Mantle baseball card is worth more than $100. I do not think a Picasso is worth more than maybe $1000. I do not think a Beeple is worth more than $100. I do not think the first tweet is worth more than $50. But clearly many people value both physical and digital assets differently than me.
So what does he own? He owns the first tweet. That's it. Like a baseball card, he can pull it out (URL) anytime he wants an admire it. He can show it to all his friends and hope they gush. He can sell it.