The problem with all economic systems is money. There's not enough of it. Alternately you could say there are too many people, but I'm not going to go down the path of suggesting genocide, so let's say the problem is not enough money. I read somewhere that even if all the money in the world was divided equally among everyone that would mean everyone only gets about $5,000. And no new money would be made because everyone would be too poor to do anything. There's just not enough money in the world for 8 billion people.
You look at all the times when there was a spectacular economic situation for some people and you see the reason is always because the world has become hell on earth for others. The US prospered like no country before or since during the 50s-70s because WW2 destroyed all possible competition and lead to the deaths of 50-100 million people. Even the paupers in America lived as kings because there were jobs galore and they paid unbelievable wages. Once the rest of the world rebuilt then the wealth of America vanished, it spread around elsewhere.
What else do you see? Places like Kuwait and Saudi Arabia where the native population does not work, at all. They can pull unlimited money out of the ground and they import basically slaves ("sponsored workers") to do all the labour for the native population who all live like kings off welfare. But that's ending too. They realise that oil is not infinite so they are desperately trying to diversify their economies so as to avoid what would inevitably be the devolution of their crapulent societies into Somalia.
I've read the literature, methane, created by bacteria in the deep ocean vents, is transformed into butane and propane under heat, and has been shown to turn into crude oil in laboratory conditions mimicking the upper mantle. Oil is not a fossil fuel, but it's not inexhaustible, just like ground water. We're extracting it faster than it's being replenished. I don't care if the Earth is "9,000 miles deep" as one Youtube commentator has expressed, you can see that technology is not advancing anywhere near fast enough to make up for the decreasing supply of available resources, be they ground water, oil, gold, or anything else. The thickness of the Earth is the problem, not the solution. It's just not possible to drill that deep, and gold or oil or whatever just isn't worth nearly enough to justify developing drilling technologies further. There's not enough money.
The only way to fix the global economic disaster that is looming fast, without starting another world war, is to discover some previously unknown magic resource to take the place of oil. There needs to be something super abundant that is extremely valuable and extremely useful as a resource and it needs to be extremely easy to attain and we need to find it soon or all hell will break loose.
Communism, socialism, capitalism, corporatism, "social democracy", they don't work because of human nature and because of the nature of the world itself.
First of all, Marx was a hypocrite who understood nothing about human nature. "When a people's basic needs are met then people will work for free. Work will be its own reward." Bullshit. Bullshit. People will not work for free, even if all their basic needs are met. People will only work for money or for a cause to which they are totally devoted (like family or religion). People will not work for nothing if they don't have to, and they will not work if there is no correlation between work and reward.
Second, planned economies don't work because it's impossible to predict the future to that degree of specificity. That's why planned economies always have shortages. A grocery store in a communist country might have one salami hanging up and you're not allowed to have it, but the party bosses can have mansions and limousines and caviar.
"But that's not real communism."
Bullshit, but let's indulge your fantasy.
"Communism works perfectly on paper but the problem is that real communism has never been implemented."
No. If by "real communism" you mean a stateless, classless society then you have to admit that "real communism" is a utopian fantasy that can never ever be realised ever in this or any world. The second you get two people together you have a hierarchy, because people have different degrees of competence so someone will always be better than someone else, and a hierarchy on the scale of a society is a class structure. You also develop a state structure, even in hunter-gatherer societies (so called "primitive communism"). This is "our" land, as opposed to "their" land. And tribes went to war with each other constantly because humans are territorial animals, just like chimpanzees. So if you're definition of "real communism" is a utopian fantasy than you might as well admit to being wrong from the start.
"Real communism" also doesn't work well "on paper" because humans won't work for free. Work is not its own reward, if it was people wouldn't need to be paid to work, and of the thousands of experiments that have been done to disprove this basic reality of human nature none has ever succeeded. No hippie commune or Marxist revolutionary vanguard has ever produced a system where people will work for free because "Well isn't that swell, I might as well help my neighbors out. And work is just so gosh darn fun too." If you worked all the time and got nothing out of it then you wouldn't keep working. That's not even a human trait, that's true of all animals. Unless you're getting more than you put in then the activity isn't worth the caloric output.
Socialism is bullshit too. Unless you have a very small, ethnically homogenous population that can pull wealth out of the ground there's no incentive to sacrifice for others in society. That's just human nature too. In-group preference. Four million Norwegians floating on an ocean of oil might pay 70% income tax to give all their fellow Norwegians "free" healthcare, but that will never work in a place like the United States where there are 350 million people of every ethnic group who don't trust each other and are unwilling to sacrifice for members of different tribes.
What happens when you have bureaucrats divvying up handouts supposedly to the people most in need? What happens every single time? They give handouts to the people who will vote them into office. Politicians buy votes by giving away "free" shit to people with low IQs who breed like rabbits because, surprise, selfishness is another part of human nature.
Maybe robots might be able to work out the system of handouts perfectly. Robots, who were deemed the overlords of humanity and had unchallengeable might, and who acted out of pure rationality and followed routines by rote without any outside factors influencing their judgment might be able to make a social welfare state work. Robots would be dispassionate enough not to be bought off by special interest groups, and if they were willing to let humans live (as pets, say), then, and only then, could socialism work. Or you might get a system where the machines decide we all must be plugged into the Matrix because humans are self-destructive by nature.
And capitalism bullshit.
The US economy is worth $18 trillion. There are 350 million people (50 million of whom are illegal). Divide the two up and you get $51,000 per person per year.
So why are there people with $100 billion and other people struggling to survive on less than $20,000?
You'll see corporations with big CEOs who make $100 million bonuses on top of the money they already make sitting on the boards of directors of six other corporations, yet they won't pay their workers a living wage. Pundits always say that the profit margins are razor thin. Well if the profit margins are so thin that the company can't pay a living wage yet the CEO can make $100 million, or with smaller businesses where the bosses can hire and promote their incompetent friends at outrageous salaries, then those businesses have very shitty business models and deserve to go out of business. If carpetbaggers can exploit their workers to make millions and not even give those workers enough to live then those people should be put in jail. It's like Citi Group or the AIG or the Goldman Sachs. Everyone in upper and middle management of those corporations should be in jail for life.
So what's left? Could post-economics work, or is it too doomed by the flaws in human nature?