Anthopologist amd archeologist have concluded that the human race began as pure socialist (egalitarian) groups that onlchanged awhen agricultural advancement meant larger communities, which has long been recognised that when a population grows in a group to a larger size will become.less social and more huerarchy/class based.
Once land ownership and division from a shared labour and co-operative group to an owner/worker worker relationship happwned societies changed.
Also sparta did ok and that is considered to have been a society that used an early form of socialism and egalitarianism.
A socialist state hasn't really ever existed no matter what a government calls itself, socialist communities however do exist and have thrived.
Until the humam race learns to not obsess about possesing things, and having ownership over land and resources and leans to share the earth equally with itself, for tge bettterment of the planet and it's inhabitants socialism won't happen,