In some states I am sure it could, not sure about all of them... Here in PA for example milk prices are controlled by the PA Milk Control Commission... they have set prices that must be paid to farmers, and minimum prices that retailers are allowed to charge...
You cannot have a loss leader sale on milk at a super market, as you cannot sell milk below the published retail price.. nor can you buy it from a supplier for less.
Some of the local farms around me will do home delivery, but their price is about double the retail price... so its more a niche operation for folks who want farm fresh milk than practical large scale, but its probably doable in some markets.
The old dairy operations were massive farms. Farms big enough to run a proper trucking operation, and to make their own cheeses and icecream and what not. That takes care of paying the farmer properly and slashes delivery costs compared to a small farm.
I don’t think I still have a milk box though.
Will need a new one.