I'm no huge fan of capitalism, but if your argument is that capitalism hasn't fully gotten rid of poverty & inequality, and needs to be replaced - with something undefined - that, to me, is essentially the argument that the rightwing uses against, say, public health care.
It doesn't matter that capitalism has observably and repeatedly reduced poverty & hunger in most situations, because something, systematically, is still imperfect.
New systems grow out of old ones. Capitalism can be changed.