The reason why socialist societies exists, is that pure libertarianism usually leads to a very unjust societies, with powerful individuals and a lot of exploitation.
Hmm. No. Read
The Production of Security, by Gustave de Molinari. The reason socialist societies exist is because monopoly leads to unjust societies, with powerful individuals and a lot of exploitation.
The answer, of course, is free markets. Yes, some businessmen are going to have more individual power than their workers. That's what collective bargaining is for.