I think the posters you're responding to are asking the following: what does an NFT provide here that any other identifier doesn't? They could just say you need to have an ID with your name on it. Is the point that would not be private? And so they could fix that by just sending you a long random string and forcing you to show that? But then is the issue in that case that that string could get duplicated multiple times and so if you had an NFT you could essentially guarantee that this private identifier is simultaneously transferable, but still effectively unique?

These are legitimate questions and I'm just trying to understand.