In order to answer this question, we need to look at the beginning and end of the book.
In the beginning of the book, there was a world of difference between men and animals. The animals all worked and labored, but they could not keep any of their labor. Men only consumed. This was one of the points that the Old Major was making to the other animals on the farm.
‘Man is the only creature that consumes without producing. He does not give milk, he does not lay eggs, he is too weak to pull the plough, he cannot run fast enough to catch rabbits. Yet he is lord of all the animals.
When the revolution took place and the animals took over, it seemed that things would get better, but not much did. In fact, it is possible to make a strong argument that things became worse. For example, there was less food, a massacre, and no retirement. Moreover, by the end of the novel, the pigs became men. So, if we look at the book from the perspective of the end, there was little difference between the pigs and men.