I disagree about the part of enough attempts and fair share, but honestly, I don't care much. Could very well be something completely different and as long as it kept the basis of no inequality, no ruling elite, free education and medical care and so on, I'd be in. I just haven't found anything that does that even half convincingly.

My belief is that similar to how back in the 18th century, they couldn't see past the following system, namely capitalism, we can't see and plan for past a classless system now, which for the moment is communism, regardless of the path there. That doesn't mean that societal evolution will stop there.