One problem I notice with voluntaryism is that it doesn’t take into account the natural elitist tendencies of human beings. Without true democracy, majorities often have a natural tendency to defer to a minority elite. (E.g. the popular clique in high school vs. the larger student body; the amount of attention models get from the general population etc.)
Voluntaryism that does not utilize democracy, requiring elites (of all fields) to make sure the general public is well-fed and educated, might result in the exact same problem it sought to eliminate.