None of the original animals are alive. (This is one of the interesting aspects of the book --- generations turn over much more quickly with animals so it's possible to have no "one" aware of the history in just 20 years.) The animals now work as hard as they did under Jones, perhaps even harder. They have no more of anything than they did under Jones. But they just assume that this is the way it is because this is the way it has always been. With no knowledge of history, what else could they assume? They have always been ruled by the pigs, so they assume that they have always been ruled by the pigs.
Their situation is probably worse than it was under Jones because now they are fuled by their own, something that seems more natural. So their final situation is worse than the first.