I expect it's an issue where the value added for the consumer is within some externality of each business, but not of the market on a whole. This would mean th

I expect it's an issue where the value added for the consumer is within some externality of each business, but not of the market on a whole. This would mean that if any farmer decides that financial profit is the main form of value they optimize for, that farmers markets become indistinguishable from other grocery sources, punishing the consumer. But if most vendors either quantify non-financial outcomes or leave them as intangible then these consumer friendly qualities are unlikely to be optimized out.