He's saying that land is the actual limited resource and therefore landowners will capture all the value that comes from upzoning. But as-of-right zoning makes

He's saying that land is the actual limited resource and therefore landowners will capture all the value that comes from upzoning. But as-of-right zoning makes it possible to use land much more efficiently than before, because the buy-side of the market really does care about housing units. So while they might still be willing to pay 50% of their incomes from housing, their demand for land will fall as housing units require less land. This will shift the balance of economic power in the favor of residents. Think of what happened with modern agriculture. Food used to be much more expensive, then we greatly increased yields. People still need food and would be willing to pay more for it, but as the cost of production has fallen, agricultural landowners failed to totally capture the benefits. Instead, society allocated resources that would have gone into low-efficiency agricultural production to other uses, such as industrial goods production.