Socialism doesn't fail because of human nature. That's hate speech that leads to genocide due to blaming innocent people for the unavoidable failure of socialism.

Socialism fails because it is fundamentally wrong about profits and free-market prices.

A profit in the free market is philanthropy because you make a profit by giving other people more valuable things than what you take from other people. That's what money was invented for: to signal who helped other people and deserved to be helped back.

For example, you take wood from the market, harming society, which no longer has access to that wood. But then you turn the wood into a chair and sell the chair.

You make a profit if the chair is more valuable than the wood.

When you harm society, you lose money, like the money you pay for the wood. When you help society, you gain money, like the money you get paid when selling the chair.

So a profit in the free market is the measure of the net poverty of OTHER PEOPLE that you have reduced.

This is possible because value is subjective: the value of things is independent of the cost of production.

Instead, socialists believe that the value of things is the cost of production. It's called the labor theory of value.

If things were worth the cost of production, an inefficient machine that produced the same good but consumed double the energy would produce double the value, and machines should be as wasteful as possible.

Under the socialist theory of value, it is not possible to decide how to allocate resources because no matter what you decide to use the resources for, it's always the same cost.

Instead, capitalism, by trying to maximize profits, tries to convert the least costly resources into the most valuable products, and profit is the measure of the good done to society.

But profits are the very thing that socialists try to destroy the most. If somebody is helping society the most, it's by making high profits. But then socialists punish the best actor by taxing him, killing the best assignment of resources.

Also, socialists cannot know the value of things because they are always trying to distort prices. For that reason, they cannot know the cost of anything or the value of the goods produced.

If bread is the most needed thing, it is expensive because it is the most valuable. Being expensive makes the bread makers profit more, so they can take more and more resources from society to make even more bread. But then socialists limit the price of bread because "bread is too important." So the bread makers cannot profit more and increase production because the cake makers take the floor, since they had not been limited in price because cake is less needed than bread. Capping the price of bread leads to a fall in bread production and an increase in cake production.

Under distorted prices, taxes, price capping and regulation, it is not possible to decide what to produce, with what quality, using what resources, or whether to save today or consume tomorrow. Nor is it possible to identify the bottlenecks of production.

Is bread expensive because of a lack of wheat, because producing cake is more valuable than producing bread, or because there is a shortage of transport trucks or chemical plants to manufacture the packaging?

Under socialism, it is impossible to find the answer.