An artist makes a painting. It’s beautiful.
Goes to a gallery, they frame it really nicely and put it on display.
Somebody buys it. The gallery takes 30% of the price and gives the rest to the artist.
Next time, the artist sees a potential buyer, quickly takes down the painting and sells it to them on the street.
The gallery owner tells the artist not to do that next time.
The artist says “But how would I sell my paintings? There’s no other way!”
The gallery owner says “There’s another gallery right over the street, look! Their frames are not as nice but they will take your paintings.”
The artist says “No, I want to keep my paintings in your gallery, with the fancy frames and pay you nothing.”
The gallery owner says “No.”
The artist says “Well, then give me your fancy frames and let me build my own gallery!”
The gallery owner says “We put a lot of work into making the frames. We’re sure you put a lot of work into your pictures to and you can try to sell them elsewhere. Good luck. Bye!”