Marx predicted that capitalism would eventually fall in on itself. To paraphrase, consumers going for the lowest possible price would eventually mean workers would have to accept lower wages to keep their jobs, but those lower wages would mean they could not longer afford the basics of life, and hence lose their abilities to be consumers.
Capitalism was abound in 1840. Then in 1848, without any help from Mr. Marx, Europe exploded. The aristocracies had to cede some of their political power to the masses, and the world’s first true progressive policies took place.
In other words, socialism saved Europe.