The basic characteristics of socialist economic relations are (a) shared ownership of the means of production and (b) production planned for common benefit rather than personal profit. We have plenty of examples of these types of economic relations in industrialized societies:
public libraries public parks public highways fire departments police departments open source software credit unions employee owned businesses food co-ops basic scientific research in public universities volunteer/charity organizations
The problem is not that these forms of socialist economic production are "mainly a fantasy"; the problem is that many people take these forms of effective socialist production for granted while they babble endlessly about how "socialism doesn't work". Socialism works just fine.
Miles