No it isn't. The claim was "provenance matters". Your claim, "but NFTs of stolen art exist" is non-responsive. Stolen art isn't the norm, it's the exception, IRL and on-chain, it's not honest to imply otherwise, and you know better than that.
The alleged promise of blockchain is that it solves the trust issue. But this discussion you are having proves that NFTs do not solve any trust issue what so ever, you still need to do research to see which NFTs are officially blessed by the creators.
Except ownership is difficult. Eventually the creators will die, and the ownership of their IP will transfer to their estate. Those estates have arguments. If two people, part of a hypothetical estate with a claim on some IP / Artwork / whatever make competing NFTs, how does "blockchain" resolve the issue at all?
Suddenly, we're back to courts and arguments. No technology seems to be able to magic-away the agreements we have with each other as a society.
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The other issue is: if you aren't using blockchain for trust, then blockchain is no better than a literal physical certificate. A fancy piece of paper with the signature of the artist.
Here's the full claim: "Provenance is a thing, so no. You're just some rando and nobody would care about your NFT."
It turns out, that "some randos" have a jolly good time on NFT platforms selling stolen goods, and it's not an exception, considering how many of them are. NFTs provide exactly zero help with provenance that "matters".
> tolen art isn't the norm, it's the exception, IRL and on-chain, it's not honest to imply otherwise, and you know better than that.
OpenSea had so many complaints about stolen art that they decided to just remove the complaint form. Because stolen art is the norm on-chain, and NFTs provide exactly zero protection against that, no matter how much you claim that "provenance matters".
It's a norm to such a degree, that it's easy to watch this in near real-time (e.g. https://twitter.com/NFTtheft).