The idea of NFTs as digital assets in game is not that they are usable in every other game, but that game developers do not have to worry about creating a market for their assets and things as transactions from user to user, so there's a lot of cost and time that's off the developers shoulder. It also enables them to earn a small fee on every resell. NFTs enable you to resell any digital asset that you own. We got so used to just purchasing items in games like Diablo, WoW, all those mobile games, CSGO skins etc etc. Even the games on steam themselves are digital assets that are owned, but can't be resold when you're done. NFT tech wants to make all digital assets transferable and tradable.
NFT technology ensures that you can trace the origin of the item to the issuer, verifiy it and make sure you can trade it p2p and then able to use it in the same game. If your argument is, but then you can create a centralized market for it, ignores the effort it takes to build that. Especially independant game studios would benefit from it. Only big monopolies are currently running digital markets for their assets and they're highly restrictive.
Suggestion is to stop trying to find reasons why you dont have to use NFTs and just think what's easier when you use them.
And to address the environmental aspect, no NFTs will be issued in mass as game items on a proof of work blockchain such as Ethereum, that got into the headlines with their energy consumption due to the mining operations. Creating assets there and transferring them alone costs between $20 - $100 per transaction. So no mass market is going to use that.
Game studios and brands are chosing proof of stake chains, because it's basically free and doesn't consume any more energy than other tech on dedicated servers. So transaction cost is neglectable. If I see people raging about the environment when it comes to consumer NFTs, they completely ignore that fact.
Mattel, Hasbro, Capcom, Sony etc have issued > 100k NFTs for free on Blockchains like WAX, which have also have a gaming focus, including verification of assets, secondary markets, smart contracts that can interact with games etc. They even have redeemables with qr-codes etc, because users can use such chains for free. And there's no mining involved. This is because the blockchain community knew for a long time that mining chains are not suitable for large numbers of users. That's why we keep innovating. Brushing all NFTs and Blockchain with the same brush doesn't help imo. Problems are best being solved from within.
