That would make NYC 5x as dense as SF. But your numbers are wrong. San Francisco's land area is 46.9 square miles. New York's land area is 304 square miles. New York's density is about 50% higher.
But it's not clear that New York shows any a path forward. They did build up, and prices are still high. Maybe that's a sign that blindly increasing housing supply doesn't actually solve the problem.