Every unregulated capitalist economy has devolved
Right, but I'm not arguing for unregulated capitalism. I think capitalism should be highly regulated. I'm arguing for fair markets that reward good actors and punish bad. I'm arguing for continually refining capitalism and fixing the problems. Which is why I keep having this argument. You're obviously an intelligent person, motivated to change society for the better, with a good moral compass. I want you on my side. I want people to want to work on the actual problems, and not pin their hopes on some big idea that will fix everything, because that doesn't exist.
Sure, there have been authoritarian governments that said they were socialist for PR.
This is the cognitive dissonance about Marxism that bugs me the most. You believe that a system such as Capitalism is so flawed that it must be replaced with something else, but you are unwilling to see that Socialism is also flawed in different ways. If you adhered to the principles of pure Marxism, you would see that Socialism as well must be discarded for a better alternative. Instead of seeing that, you will label every failed Socialist state as a fake. We need something else.