No one can tell the difference, besides by using techniques like a ledger or scientific analysis. Both can be easily tricked by anyone involved. This means your perception of those items is strongly colored by completely external "facts" (rather, assumptions based on your trust into experts, at best). We could show the countless tourists that want to see her a replicated Mona Lisa and no one would ever be able to tell. Yet if we'd tell them there'd be at least a small outroar.
All of this is really off putting. Reminds me of placebo. And being emotionally invested in sports teams.
I would suggest that this is because you place no value on the act of creation, the creative genius that pulls the artifact out of thin air into the material world. The view you are describing is purely utilitarian.
The counterfeiter is stealing that creative value, without which the artifact they are manufacturing isn’t possible.