It simply means groups need to adapt to the realities on the ground. Your 1,000,000 milk drinkers may be better off measuring existing players vs buying milk collectively.

Dealing with information asymmetry not distribution can result in better outcomes without expending nearly as many resources.

PS: Consumer reports is a solid example. Collecting a lot of information on each toaster/fridge/bed is not practical for an individual, but split that among 1,000,000 people and each can save more money than the cost of a subscription.