Marx sounds like a boring optimist. To be clear, I don't think there's anything wrong with optimism per se. It's just naive and superficial.
I don't think we need a rearview mirror to look at communism. China, and Russia are encroaching on everything. You have probably heard of all the recent cyber attacks waged against America. And capitalism, nor Christianity has an answer for those Godless heathens.
When your enemies are subsidizing cyberwarfare you should probably match that energy. I'm not trying to sound an alarm here, but every time someone implies "socialism never works" I'm always annoyed and amused at the same time. At the pace America is going, we will lose the wars of the future if they are against the communists. We will lose badly.