It doesn't make a difference whether EPIC provide a public API for querying a users profile for what trophies they have, or whether EPIC put that information on a blockchain.
NFTs also don't help digital artists in that NFTs don't prevent copyright infringement. A certificate of ownership can be placed in a blockchain, with a hash, but unless you have a copy of the art to hash then you can't verify it. Once you have a copy of the artwork, you can just ignore the blockchain or claim ownership on a less reputable blockchain. So again, reputation of the organisations minting tokens on the blockchain is key.
This has been touted for years now.
It's not something studios are going to want to support, nor code for - how does this item behave in an entirely different game by an entirely different publishing house? Do I have to write my game to support every single possible one of these? Why would I let you bring your level 9000 sword of whacking into a new game?
And steam can already easily make something unique - they are the authority there, there's no need for trustlessness.
(edit - you know what? Proof of ownership is not the hard part of transferring assets between games, it's likely to be pretty darned easy to do that just with a database. Textures, models, in-game attributes, all that stuff. That's the hard problem there, if anyone even wants to bother.)
All an NFT is is an encrypted hyperlink in the blockchain. The hyperlink points to a resource on someone's server. I think people forget that the NFT doesn't store the real thing. All an NFT is is basically an encrypted DNS server with some ownership data attached to it.
Right now you could showcase your Fortnite trophy in SteamVR IFF Valve and EPIC decided to integrate this. Using regular boring techniques.
Blockchain doesn't make this easier in any way. All Valve could do is get what trophies you own from the blockchain. But they'd still have to integrate with that particular blockchain and with the systems from EPIC that host the actual thing.
Having a regular database/account system would be way more efficient and easy to use tbh. For example I can already showcase my Tweets on LinkedIn due to regular boring integration. Data from two different companies shared by establishing that I am the owner of both things via a regular old token. Data transferred via an API.
So if someone moves urls around on the server or if the company goes bust, that link is dead.
NFTs could become gamechangers, in the literal meaning of the word. The project Enjin for instances focuses on NFTs in the gaming world. One selling point is, that you might be able to collect items in one game and transfer it to another. Collect a rare trophy in Fortnite and show it off in your Steam VR Home, the trophies uniqueness and legitimacy verifiable by everyone. Of course, achieving this is easier said than done, but an appealing vision for the future of gaming.
Also, it has historically been difficult for digital artists to get paid well, considering that copying their work is easy. I'm all for changing that. Yes, the image can still be copied, but ownership is it's own thing and some people are willing to pay for it.