Right, because the creator of the NFT totally can't just mint another token right after you buy the first one. Oh wait, just kidding they can. And there's absolutely nothing you can do, because you don't _actually_ own the thing, you just own a trivially replicated pointer to the thing.
It's ok though, because at least the original will definitely be the one to be valuable, and not the 42nd, 69th, or 420th. Right? Right??