Andy Warhol disagreed. But in general: it's not a bulk or commodity business like, say, toilet paper, but an artist that creates five thousand works a year can definitely out-sell an artist that creates five.
To the extent that art intersects capitalism, that matters (even if the second artist is charging thousands per work; when your price is too high, people can't buy, so the artist charging dozens or hundreds per work but making 5,000 a year can sell to all the people who can't afford five-works-a-year).