You can do this too already. IIRC there's a web-based character viewer for WoW that lets you see equipment/stats/etc. I'm not sure what NFTs add here other than the remote possibility that you will be able to use the same NFT in a different game. The chance of this happening across franchises is vanishingly remote in my opinion though.

Using NFTs for loot like this also gives a great excuse for publishers to make more games online-only, which is a net-negative as far as I'm concerned.