Socialism works in commune settings and families, where the relationships overcome the tendency not to pursue self interest. But it would be foolish to project such a system on a country, especially one that is ethnically, religiously, and racially diverse. There are zero examples of socialist economies being self sustaining over time, which is why they eventually abandom socialism even if they preserve communism (like China).

Socialism relies on what is best called "kinship" without it, it simply does not work, the less homogenous a population the less it works.

Communism is where only one party exists that runs a country. Having toured communist countries, you are correct that communism works if you are a member of the party especially an important member or official. It does not work that well for everyone else. Inherently selfish people are put in control of the distribution of goods and services and as such they make sure they get the best and "crumbs" go to everyone else.

Early Christianity had a commune structure comprised of like minded people who shared a kinship based on religion. That simply does not fit with the demographics of most countries. Furthermore, Christians were working for "eternity", not something a more secular humanist society is going to "buy" into.

It should be noted, America is such a free and open society, that citizens routinely opt to join communes and adopt socialist and in some instances communist structures within the commune and no government entity tries to stop them. The difference between is when government coerces behavior and as they say, that makes all the difference.

While some communes have grown quite large, they typically collapse in time due to corruption from within. Not surprising... unlike countries, these communes can't call on the military to put down dissent...