The big pitch was that you could have non-copyable items which you could move between virtual worlds. The Second Life / Open Simulator ecosystem already has that problem. People looked into NFTs as a way to solve it, and concluded it would not help.
You can download content and upload it as new content, perhaps with a minor mod, creating a new object. This is called "copybotting" in Second Life and Open Simulator. As with any copyright violation, you can file DMCA takedown requests if you find a copy of your stuff.
Would NFTs stop copybotting? No. They just protect the object's ID, not its content. You can still copy the content. If you want to copy a Bored Ape Yacht Club NFT image and make a poster of it, the NFT system does nothing to stop you. It's not even clear that's a copyright violation in the US, since BAYC images are computer-generated.
Many NFTs don't even have an on-chain cryptographic hash of the content, only a URL for some server. Nor do most NFTs have their NFT ID watermarked into the actual content. So the NFT doesn't even give you a verifiable proof of ownership independent of the creator's server. There isn't info that would allow a server to tell if a new image upload is a copy of an existing item. An image search might help, but that doesn't need NFTs. Decentraland's solution to this problem is to charge a $500 "curation fee" to get an object onto their platform, which cuts down content to the point that they can check for duplicates.
NFTs are thus useless for their claimed purpose.