>> composability
> Not sure what you mean by this.
Yeah, I wasn't sure, either. My only clue was that there are some NFT proponents that talk about different applications using NFTs as content in the app. But that's just URLs. There's no need for the blockchain to do that. And when you start talking about things that go beyond simple aesthetics, like NFT game items/cards/weapons/etc., there are a lot of problems that either don't go away or are made worse by the fact that there is a supposed "real world value" and "ownership" tied to the objects.
There are a number of NFT Tradable Card Game projects in the works right now. And they sell themselves on the premise that players "own" the cards, and that the cards can be taken "elsewhere". But I think it pretty clearly starts to fall apart when you consider that digital TCG cards have no value outside of a game application in which you can play them, that said value is dependent on the game app not nerfing the card stats or the interpretation of the card stats, or debasing the value of existing cards by releasing new packs of more powerful cards, and that there is no incentive to any app accepting cards minted outside of their own structure.
Wizards of the Coast owns Magic the Gathering. I can't make MtG cards and call them MtG cards without violating WotC's trademark. I can't produce copies of MtG cards or the rules of MtG without violating WotC's copyright. Any cards I create that are not a part of MtG's ruleset are meaningless in the context of the cards inside MtG's ruleset. Regardless of those issues, WotC's incentives are to control the balance of the game in such a way that keeps people buying cards from them, so they have no incentive to interoperate with any of my cards, as they could potentially upset the balance of the game. And finally, WotC is well-known for deprecating old cards (if it's not usable in the game, then what value does it have?) and releasing new decks that make old decks worthless (a card's value is only definable in relation to how well it plays against other cards).
The NFT-ness of any of those cards doesn't change any of those issues. If anything, where MtG players can subvert WotC's shenanigans is in playing house-rules versions of the game. Which, again, won't be possible in an online, digital version because of copyright and trademark issues. So where physical TCGs have an out for groups of friendly players, because you have actual, physical ownership of those pieces of paper, NFT TCGs remove that ability, because they are useless outside of the context of a large, legally-targetable entity capable of deploying a competing application. It's as if you bought MtG cards, but the only place you were allowed to play with them were at WotC-sanctioned events.
And that doesn't get into the concept of the "value" of special versions of cards, like foil finishes, which are no different from standard versions of the cards outside of strict aesthetics. You may have bought a token that says you have access to play that foil card, but you don't have rights to the digital asset file, © WotC.
One of the key components of a concept of ownership is the ability to exclude others from access to the thing that is owned. NFTs do not provide any concept of exclusivity of the actual asset, only of the token. It becomes a Prisoners' Dillema in which the only way the system works is if no actors within it defect and take the assets without acknowledging the "legitimacy" of the token or the blockchain as an authority.
It's particularly funny to me to see the drain-swirling relationship to TCGs that crypto-* has had over the years. First with Mt. Gox (which was not a mountain named Gox, it was Magic The Gathering Online eXchange) becoming a crypto-exchange, then the controversies there, now NFT TCGs ala MtG.