Socialism in a nut shell.
Marxism assumes a zero sum pool of wealth and resources which means that in order for one to have more others must have less. While Marx argued with Malthus on detail they agree in effect on finite pools of resources and thus wealth. Hence war for land, resources, unskilled labour and power all of which are seen as raw resources. Hence the famines. Hence green socialists limits to growth and overpopulation arguments.
The capitalist idea that an entrepreneur can turn a non resource into a resource is rejected by them. The fundamental underlying misunderstanding of Socialists is this limited sum theory of economics.
Their secondary error is that capital does not decline over time. This is the other thing the capitalist is doing. This is what his unspent wealth is really set aside for. The gold, the bank, the yacht, and Lear jet are just placeholders. Wealth you can move easily in the latter two cases.
Socialists seize and deplete depreciation funds, rainy day funds, insurances, and investment reserves. This leads to systems failing for lack of provisional and maintenance funds.The oil rigs in Venezuela seize up, the railways in the USSR rust and Californian roads crumble.