Most art is owned privately and stored away (as an investment). Most art that's owned in a museum is stored (and is "donated" to the museum by the private collector).
Also part of the problem is that art is fragile and showing say: a painting can degrade it, as light breaks up pigment. Even in storage, certainly paints/mediums change their physical characteristics. Many "hidden" paintings reveal themselves underneath the oils that make up the final painting as the medium becomes more transparent.
Maybe it should be more clear to the public if the idea that art isn't so much given to museums, rather that artwork is used as a speculative investment by a private party until such a time it makes financial sense to transfer it to a museum. There is also the fact that if one is powerful/influential, you can influence the value of the artwork just by owning it and keeping it out of circulation. The whole private buying and selling of the artwork from gallery owners to auction houses works to raise the value of the artwork through hype, really.
It can be a hell of a grift.
van Gogh wasn't very good at playing that game, even when his brother was an art dealer - that's such a leg up and he blew that advantage. van Gogh isn't known to be all that easy to work with. Attempted murder doesn't help with this. We know him know since we celebrate his mental illness.
You make a number interesting points. FWIW I've been a printmaker for many years and know many artists "successful" and not.
Museums acquire work through purchase and donation, the ratio varies among museums and divisions within a museum. Several years ago a collector donated several thousand pieces to the major museum in my region. Fortunately a few of my pieces were included and are now part of the museum's "permanent collection".
Obviously museums prefer donations but only if the museum gets the kind of work they're seeking. It's a lot like academia, very competitive among curators to have the "right" high-valued work in the museum's possession.
And it's true that an artist's success is largely a marketing game. Artists who are good self-promoters will do the best. Those who aren't typically remain obscure. Of course success doesn't necessarily indicate artistic merit. That's often not decided until much later, like 50 or 100 years down the road.
Conservation of work is a complex subject. Oil-based paint was the only real option from the 1400's until ~1960. Oil paint dries by polymerization of fatty acids, problem is it doesn't know when to quit.[0] A paint film continues to harden, eventually the film integrity fails and the paint flakes off the substrate (canvas, etc.). Oil paintings are very likely to require restoration after 100 years if not sooner.
Worth noting: unlike works on paper, oil paintings are less affected by light exposure. That's why museums often display paintings in brighter areas (200 lux) vs. drawings, prints, photos being exhibited in dimly lit galleries (50 lux).
Interestingly many great artists were lousy technicians. Da Vinci is said to have experimented with various additives to paint which affected stability. Fascinating subjects indeed, and certainly contribute to keeping conservators employed.
Also part of the problem is that art is fragile and showing say: a painting can degrade it, as light breaks up pigment. Even in storage, certainly paints/mediums change their physical characteristics. Many "hidden" paintings reveal themselves underneath the oils that make up the final painting as the medium becomes more transparent.
Maybe it should be more clear to the public if the idea that art isn't so much given to museums, rather that artwork is used as a speculative investment by a private party until such a time it makes financial sense to transfer it to a museum. There is also the fact that if one is powerful/influential, you can influence the value of the artwork just by owning it and keeping it out of circulation. The whole private buying and selling of the artwork from gallery owners to auction houses works to raise the value of the artwork through hype, really.
It can be a hell of a grift.
van Gogh wasn't very good at playing that game, even when his brother was an art dealer - that's such a leg up and he blew that advantage. van Gogh isn't known to be all that easy to work with. Attempted murder doesn't help with this. We know him know since we celebrate his mental illness.