Capitalism generates capital. Yay for us, we now have lots of capital. But once you've generated all the capital, and maximised all the profits to the point of driving surplus value to 0. What then?
* Also a major nitpick, most of that billion were brought out of poverty in China in the 1950s at the peak of Maoism/Communism... so you're point is kind ironic, no? The majority of the remainder were also in China during DengXiao ping driven state run capitalism or "Socialism with Chinese Characteristics"... So even if you weren't missing the point, the point you are making is still very moot.