tl;dr - true capitalism results in economic singularities and infinite wealth for everyone. that’s why i like capitalism as a leftist.
to get us started, my definition of capitalism is “unregulated competition”.
i ask because… …i really like capitalism. but i’m a leftist.
i am someone who has been called numerous 6 letter words my entire life by people who think i’m a socialist or communist. but i’m really not.
it’s funny really, those calling me a f##### can’t handle real competition. especially at this point in a planetary species’ development. where nimbleness, flexibility and cooperation among economic partners is more profitable than most government intervention. obviously.
government is meant to ensure security, authenticity and veracity of economic claims. not limit markets with patents or unreasonable prohibitions.
i think authentic capitalism is wonderful and the ideal choice for a free society.
Aside from your odd definition of capitalism and its outcomes, which other people have addressed, the answer to the headline question is: yes.
Karl Marx, for example, believed that you could not have capitalism without exploitation and that it was therefore an unethical system that should be defeated. He also held that capitalism was inherently contradictory and that it therefore not only should be destroyed, but that it must be destroyed.
However: Marx also believed that capitalism was an enormous improvement on the previously existing social system of feudalism, because it produced far greater wealth through the development of new technology. This is a key difference between Marxism and the earlier ‘utopian socialism’ (which his theories largely replaced), which saw technology itself as an evil.
Marx also welcomed the fact that capitalism destroyed (as he saw it) some earlier forms of oppression (albeit while introducing new ones). Marx’s letter to Abraham Lincoln congratulating him on his re-election discusses the American Revolution and Civil War in precisely these terms.
So, you can enjoy the greater (obviously not ‘infinite’!) abundance of goods that capitalism has produced, you can acknowledge its positive impact on technological development and its material improvements of the lives of millions of people and be not only a leftist but a fully orthodox Marxist… just so long as you also acknowledge that capitalism is also an exploitative and self-destructive force that should, can and must be defeated.