I personally don't get this attitude, but I also don't understand a lot of what draws people to museums when we have photographs of works of art. Which is not to say that I don't get why people view works i n person. I just don't understand neurotically trying to preserve a physical work when the author likely didn't even care that much or consider a more preservable medium to begin with.
I'm not clear that the original artist's materials, with respect to longevity is really relevant, assuming the artist didn't explicitly intend it to be ephemeral.
With that being said, I’m sure they could make a replica that would be almost impossible to tell apart from the real. After all, this technique was specifically invented for mass production.
Is there another option? Even sculpture hewn from rock is ephemeral.
As for why these pieces should be preserved even if their creators were sometimes sloppy about doing the original legwork. Well, in the case of many famous works, they're literal pieces of history dude. Choosing how often and when to display them isn't just about "optimizing viewership". These aren't blog posts or IG reels. It's also about saving their literal existence for as long as possible.
Just 200 years ago, in a world without most of the technologies we take for granted today, art played a fundamentally representative role in stretching the boundaries of ideas, imagination, possibilities, and in extension, human cognition and social impact.
Preservation is the point. Art is made in the moment. Yeah there can be scientifically proven ways of longer-lasting / preservable mediums, inks/paints, etc. Pieces of art capture inspirations and ideas of the creators and pass that feeling along to future generations to also be inspired with new ideas for their times. They can be a snapshot of one place, at one moment in time, but they can also be timeless.
Though I'd imagine mostly its going to be a random sample of people that happen to be there that day. I imagine there's likely under 1% of museum visitors actually chasing single works and planning trips like that. So most people that would see it are still just random "museum people" (which under the "interest" metric is still better than purely random people).
We should auction off the visitor spots, then.
0: https://www.munch.no/en/The-Scream/where-can-i-see-the-screa...
An example: my partner is working in a relatively expensive "wellness" service. Some people reserve and never show up even though they have reserved for a whole family and lose more than a thousand euros. I am pretty sure a lot of people that cannot afford this service at this price on a regular basis would if it was less expensive for them. I know I do as I only profit from it because I have a 50% discount and my partner doesn't have to pay so we pay a quarter of the price everytime we go together.
So making it an auction and you would still see a mix of interested people and vain but wealthy people for which paying for this would still be pocket change and would just take an "I've been there" selfie and move on without really being interested in the artwork itself. So more money for the museum but not necessarily representative of the interest of the visitors.