I think you make a lot of great points as to why dumping NFTs as a concept into a game won't give it any additional value. I've thought about this issue a bit while discussing it with my friends and I could only think of two potential points that NFTs bring to the table (and still, they are rather contentious):

• Leveraging on battle-tested marketplaces: With NFTs released on a certain chain, you get access to all the marketplaces already available on that chain (e.g. OpenSea for Ethereum, TokenTrove for IMX). There's no additional work required to create your own marketplace for your game's NFTs should you wish not to.
• Real Money concerns: I'm not too sure about this so correct me if I'm wrong, but I think a key reason why most games don't deal with real money marketplaces is the amount of legal work that is required across countries. With NFTs, maybe they get to bypass this?

The rest of the features of in-game items, as you've said, can be implemented without NFTs/blockchain in any way.