Because the NFT isn't the t-shirt. You can own the NFT and the physical t-shirt, and sell the NFT to someone else but give them a fake t-shirt. They don't suddenly have a real t-shirt just because they have the NFT.
> You can own the NFT and the physical t-shirt, and sell the NFT to someone else but give them a fake t-shirt
That's a very smart way to achieve nothing. You now have created an actual copy on a shirt, at your cost, and proceeded to still own a shirt that has no market value now that you don't have it's authenticity proof. Seems like a very smart thing to do.
NFTs were created for the very reason that certificates of authenticity have no value unless the ledger from which they were issued is not public.
How can you know there wasn't more certificates printed than tee shirt created ?
How do you know it's a real certificate in the first place ?
How about you loose the certificate ?
Seriously there really is no reason to not prefer a digital certificate versus a physical one, it is on all accounts superior.
You certainly wouldn't argue cryptographic keys are useless because we have physical ones on any other matter if it wasn't for following the "I don't like blockchain" trainwagon.
You don't raise any problem specific to digital certificates here, but rather just the ones that are present on physical ones and still present on digital ones. No solution is perfect, but it still removes a lot of the previous ones. And for each of the issues, the digital solution is far superior / more efficient than the physical one.
> What if you lose the private key to the NFT?
Just the same as with physical certificates that you loose. You maintain a revocation list and ask the original artist to issue a new token for you after attesting your piece authenticity himself.
> What if you sell the NFT with a fake item?
No system on the planet can prevent you to do that, unless you were able to non destructively watermark your art piece, which has been tried and failed a billion times. Preventing you to display, resell, and risk of prosecution has proved to be a good enough deterrent. If you have a solution to that problem, feel free to disclose it, we will all trash NFTs and switch to it. Or maybe not, because you would still have to store _somewhere immutable_ the actual fingerprints of the pieces ...
> What if the blockchain splits and there's now two NFTS?
You don't have to care about that. At the time of selling, if the buyer asks you to choose either fork, trash your NFT on the blockchain you don't want to support.
Honestly just replace "NFT" with "SSL certificate" in all your questions and you will have an answer.
> What if people collectively think that NFTS are stupid and forget about them, so now the physical item owners are no longer the same the NFT owners?
How do you think that works at the moment ? countless art galleries that certified art provenance checks do not exist anymore. Are you arguing you would prefer chasing down old employees / experts to check your paperwork than run a signature check...?
Before criticizing NFTs I suggest you try to think deeply about what it means to actually work with physical authenticity documents.
