According to Marx's theory of immiseration, what does capitalism eventually lead to?

When businesses compete everything is great. Eventually one of the businesses in a field gets bigger. And bigger. And bigger. It buys out it's competitors. It monopolizes it's niche filed, sometimes even spreading to others. Since money will no longer be used, people will have access to all of the resources they need, and there will no longer be a state to protect the capitalist's private property, I find it extremely unlikely that a worker would want to exchange his labor for a wage. The way I see it, it would be like playing pretend. The situation would be similar to if a group of people in the United States declared their friend Tim the king of Arkansas.