Most large successful worker co-ops make up the majority of their profit through the exploitation of part-time and seasonal laborers that are not on the same pay-scale and insurance plans as their full-time and co-owned employees. They then limit their full-time employment to a certain number of individuals, usually by understaffing, dangling the possibility of fulltime employment at these part-time members, but also by exploiting the surplus of third-world workers.

Co-ops within a capitalist market context cannot escape the basic wage-labor exploitation that is baked into the system and compete at-scale with larger more hierarchical firms.

I have worked for multiple worker co-ops in the U.S. and this is usually the case.