Why were oppressed populations attracted to communism

The oppressed populations were very attracted to the communism because it offered something that they have always wanted, equality in the society, more or less a horizontal hierarchy.

The communist parties promised to the people that all of them will be equal, they will have the same rights, the same opportunities, everyone will have the same wages. The richer people were not fond of this philosophy at all, but the majority of the population were the poor people, and that seemed very attractive to them.

Unfortunately, the communist parties, once they gained power, were not acting as they were saying they will. In fact, the people ended up being suppressed by dictators again.