This is why socialism or communism can never work in the real world.. Human nature dictates that those in power accept perks, they use their power to enrich themselves and their friends and families. This creates an "elite" class that was so accurately portrayed as "pigs" in the Orwell novel "Animal Farm."
In a free capitalist society, this elitist enrichment also occurs, but at least the people are free to pursue their own best interests instead of having that interest subjugated to the state and ultimately the elite who control it.
Also, there are hungry want to be's who use the capitalist system to create new wealth for themselves. Elites in a capitalist system often don't stay at the top very long before they are replaced by new elites. Elites in a dictatorship have the ability to thwart potential competitors. Unfortunately, this leads to stagnating societies and economies.