It doesn't even work that well at the local level. The Kibbutzim in Israel were socialist for like 70 years, but now are almost all mixed market capitalist in some form or another.
Do Kibbutz have highly paid CEO's that earn much more than the members, and subject them to pay cuts?
As pointed out in this thread, a Co-op is socialist internally by sharing wealth across more of the labor. But capitalist externally since it sells to a capitalist world.
