What kind of Marxist crap is that?! 😁
More seriously, yes, economics dominates both politics and religion in the modern world. However, most, if not all, socio/economic/political models will work, and work well, if we assume that people are good. The question is, which model works the best for how people really are? I don't have an answer to that question, and neither does anyone else. That said, we can definitely say that some paradigms have been more successful than others. Still, we can't necessarily attribute the more successful paradigms to the model, as the populations are different.
Let's take guns, for example. Australia had a bad day with them back in the 90's, and decided that was enough, and guns became way, way, way more restricted. The US has bad days with guns pretty much daily, and there's no way that Americans will restrict guns. Different population with a different mindset.
In any case, for a democratic capitalistic society to work well, at the very least, we would need people to be educated far, far, far more than they are in the US (and, I dare say, anywhere on Earth). But, I think we can all agree that most of us in this thread (save Bob, obviously) are pretty well educated, so, obviously, education is not enough. One has to also be willing to sacrifice at least some personal gain in the interests of a better society (and people's idea of what and how much to sacrifice varies wildly, independent of intelligence or education), and one has to also be willing to tolerate difference (which, again, varies wildly from person to person and the nature of the difference).
So, no, Marxism will never work as well as theory on a large scale. Same with capitalism. Same with socialism. There are simply too many variables that muddy the waters. But no matter what the system is, people can sacrifice a bit more than they do for the common good, and people can be more tolerant of others. If we instead focused on that, things would improve, but there will never be a utopia or anything even remotely close. If only because:
"Did you know that the first Matrix was designed to be a perfect human world? Where none suffered, where everyone would be happy. It was a disaster. No one would accept the program. Entire crops were lost. Some believed we lacked the programming language to describe your perfect world. But I believe that, as a species, human beings define their reality through suffering and misery. The perfect world was a dream that your primitive cerebrum kept trying to wake up from. Which is why the Matrix was redesigned to this: the peak of your civilization." - Agent Smith
The bottom line is that humanity sucks. Always has, and always will. Sometimes humanity sucks more, sometimes it sucks less. But the problem is with the people -- everyone already thinks they are good people (does anyone actually believe that Hitler, Stalin, Mao, Pol Pot, etc., etc., etc. thought that they were anything less than good people trying to make the world a better place?). Of course, some people, like me, realize they are shit, and, on occasion, try to do something good to balance out the rest, and at least come out closer to neutral. And, also of course, there are some evil people who full on know they are evil and some good people who just do what they do, but I think they're a small minority. Most evil/bad people think they're every bit as good, if not more so, than good people.
So, how do we get people to be more good? No freakin' clue. I can't even seem to make myself more good. I mean, some things I would have taken as a given, such as when a cop executes someone that they are held accountable 100% of the time instead of what actually happens. If people in higher positions, either politically or economically are not held more accountable, as opposed to less accountable, as things are, then, no, things are not going to get better. But how do you hold people accountable? You need good people to do that. And all too often, good people in a position to do so (or, at the very least, less bad people) commit "suicide", "fall" out of buildings, etc., etc., etc..