Why classic gaming names like Atari are still going in on the blockchain

>What value is the NFT adding exactly?

That you actually own the item.

>Just that you seem to be ascribing a whole lot of importance to something that's basically just a technical detail.

There are implications of technical details. Take for example Valorant. Once Riot is done supporting the game you will never be able to play it again because the multiplayer uses centralized servers operated by Riot. To everyday users they don't really care and arguably they get a better, more consistent experience. But there are users who do care about the ability to be able to play the game when Riot no longer wants to operate the servers for it.

>Video games can already let you trade items between each other

Not really. If I wanted to trade a shulker box of totems on a Minecraft server for a CSGO skin without being scammed there is no way to do it. Games don't naively support it. If all the items are on Steam, Steam lets you trade items between users. But now you are relying on a centralized platform to facilitate this. NFTs offer a solution that is trustless and doesn't give even more power to Valve's monopoly.

>This is not a technical problem, this is a "I want games that do this, but nobody building games wants their games to do this" problem.

Now that NFTs exist a lot of the technical problems have already been slowed. Games aren't doing this because there aren't any big benefits to doing it. Games would be weakening their monopoly by giving power to the users by letting them use NFTs instead of just their own item system.

I'm not aware of any set of games that let you transfer items among them using a blockchain either, but this doesn't matter. Here's how it could work.

First of all, before being able to transfer items there's some preparatory work that needs to be done, regardless of whether you're going to use a blockchain or not. You need the various game designers to agree on a common format to encode those items, so that the different games will be able to parse the data when trying to import a new item. Ideally, you would like everyone to agree on a single format, but even having just a few groups of developers to agree on one fixed format wouldn't be easy. After that, you have to solve two game design issues: which items makes sense to transfer from a particular game to a particular other game and how to map the different attributes between the two games in a meaningful way.

As an example of the first problem, imagine what would happen if you were allowed to tranfer automatic rifles from Call of Duty to a RPG game where you are supposed to fight using a sword and a shield: you would ruin the latter game. As an example of the second issue, I never plaied World of Warcraft, but I think that WoW swords have very different attributes from Minecraft swords, even if on a superficial level we're talking about the same item, i.e. a sword.

Note that this preparatory work is the hardest part to do, because it isn't a mere technical problem but involves many other aspects. And you need this regardless of the actual technology that you're going to use to transfer the items.

After we solved the above problems we get to the transfer part. Sure, you could use a blockchain, but do you really need it? Here's an alternative way: when the user decides to transfer an item from game A to game B, game A's server sends a message to game B's server saying: "User X wants to transfer item Y, here's a description of item Y in the format we agreed upon. Do you accept the transfer?". Assuming that we solved the initial problems, implementing such a protocol is easy enough that most BSc students could do it as part of a software engineering course. A possible question could be how the two games would know that they are talking about the same user. There are different possible solutions to this, an easy one could be to use OAuth to authenticate the user.

In the end, the proposal of using blockchains to transfer game items is little more than using a blockchain as a database.

Your original question was about the existence of other technologies apart form blockchains allowing for transfer of game assets, and I answered that. My two main points are that there are other ways of doing it, and that the core issue is more about opening a canworm of game design problems rather than finding a technical solution to the exchange of information between games.

I still think that the added benefits of using a blockchain in this particular scenario are very little and not relevant in practice (e.g. a game studio doesn't close overnight, so users would have time to transfer their items somewhere else and I think no bank would accept my Minecraft diamond sword as a collateral for a loan), but these are my personal opinions and as such are debatable.