And they already do that. The third party is states backing traditional banking systems.
There is value - with a trusted third party, you are "trusting" that the third party will stick around, won't block you, and won't arbitrarily change the rules on you.
Worse, if your game currency is a decentraliced ledger, then it's much harder to do something about the rogue participant. That's by design. If it's instead a central entity, they can kick out that party on a whim.
[edit] Just try and leverage some NBA Top Shots on your own website and let me know how that goes.
> But the point being I do believe theoretically there are "legitimate" applications where the decentralization of assets is useful.
It's been 14 years, it's not still early, there's just no "there" there.
Although I agree with everything else you wrote, I don't think this follows.
As a counterexample, Secure Scuttlebutt was created for a specific problem, which was that the creator was a sailor and wanted an offline-friendly social media platform. By using a blockchain, users would have a copy of the database locally that they could interact with and then synchronize when they either cross paths with other sailors (because as long as there's a local network, they can synchronize with peers without the need for internet access) or reconnect to the internet. In this case, the blockchain is relevant in that it enables the network to work independently of internet access and provides decentralized eventual consistency guarantees. A centralized solution would unavoidably require internet access.
It's not a million-dollar idea, and further development is fragmented due to there deliberately being no centralized leadership of the project, but it seems to fit its intended niche use case.
In practice, nobody's doing this (even those game devs who are minting assets as NFTs are keeping the assets to one game, making the whole exercise pointless) and it seems probable that nobody really wants it.
But the point being I do believe theoretically there are "legitimate" applications where the decentralization of assets is useful. I just have yet to see an example in the wild (or even to imagine a concrete thing I could make where this would really be the case).