Of course there is voluntary socialism.
If I listed examples. . . it would send you into a tizzy of denial. . . and you would object, saying. . yeah, but. . but. . but, THAT'S NOT SOCIALISM.
Ever since the founding of New Harmony and Owenism, Americans have tinkered with it and perfected it. Americans, upon observing how the Native Americans did it, know how to do it.
You have been propagandized and brainwashed by the oligarchy, thinking that the only way it is done is through the state, and it can work no other way.
You either carry your weight in the mutual society, have a valid and legitimate reason not to be doing so and be drawing on the resources of the community, or? YOU ARE OUT.
The following is an example. . . but I lived in a living co-op when I was in college, small farmers participate in farmers co-ops to support each other, there are energy co-ops, and credit unions, all sorts of ways to help each other out that don't depend on the corporate structure. People over profits man. People over profits. And it is all voluntary participation.
No different than the basic tenets of socialism. Your problem, is you believe that socialism is defined as GOVERNMENT COERCION. The very first experiments in socialism were VOLUNTARY.
en.wikipedia.org