The post is written like as if consumer coops is a radically new idea (spoiler: they're everywhere in Europe). Unfortunately they have long since succumbed to the same mechanisms as their competitors and have a tremendous power concentration in top leadership, with directors making ridiculous salaries. On paper though, e.g. Coop with a 25 % market share in Norway is owned and controlled by about 1 million of its customers.

Hah, so this. USSR had it formalized in form of PotrebCoop, literally consumer cooperative in 1921.