In any society, some people will be leaders, some will be followers, this is natural. You cannot have a society without someone organizing the work and setting the course.
Of those who are naturally leaders, some will be much greedier than most. Some will also be ambitious, corrupt, two faced etc.
These people will do their best to gather wealth and power for themselves, be it in a capitalist or communist system. In the capitalist system they’ll become entrepreneurs if they also have good business acumen. In the communist system they’ll become managers and state officials if they can also navigate politics well.
At the end of the day, the same people will get to power and will hold dictatorial control over the means of production. In communist countries a literal dictatorship seems inevitable, while capitalist ones usually favor democracy (can be better for business) but they can also descend into dictatorship.
If you disagree, show me an example where all this is not the case. I’m honestly curious