Picture the time in which Karl Marx’s Communist Manifesto emerged. The Industrial Revolution, unraveling in full force, was very much based on a materialist world view. Since physical resources are limited it’s only normal that someone, Marx or otherwise, would have signaled that a zero sum race for wealth will make some extremely rich only at the expense of others. And indeed there was some truth to that, as exceedingly ambitious industrialists seemed to have no limit to their greed. There’s no leap of logic required to arrive at the “class warfare” idea aimed to right the inequities generated by a zero sum game world. Accumulation of things, cordially known as consumerism in our time, was also decried by communists as a sickness of the soul.