Sergarr, everything about what you wrote is wrong.
Communist countries sometime enjoyed high standard of living.
Cuba is a developped country according to standard of living index, and that's despite the US's embargo. Cuba is communism's best case scenario, with cold war ear-tech... which also showcase the issue with communism : the centralized everything tend to create totalitarian states.
The US didn't rise to the top because they were the best at everything.
The US domination is a product of the XXem century. In WW1, the US gained a inconceivable amount of money selling weapon and supplies to the allies. At the end of the war, the allies were seriously indebted to the US, and they could get what they wanted.
At the end of WW2, the US were rich beyond imagination, had taken all the best German scientist (which were the best in the world) and the bast among them even migrated before the war because an huge number of the History's best scientist were German jews, (Von Neumann, Einstein, Weyl, Max Born...). The Dollars became the world's reserve currency and it became the leader of a group that included every richest nation on earth.
In addition to that the country have a low population compared to his size, and thus huge natural resources, and a very defensible position.
Finally it defend big business's interest so have the support of industrialist world-wide, and they tend to be richer than the oppressed masses.
However, the US's own population's living condition are rather poor : Access and the quality of education and health-care is low for a developed nation. Infant mortality is high, worker's right are very low compared to any other industrialized nations, Median wage is low, especially compared to average wage, public services such as public transport are all but non-existent, incarceration rate is the highest in the world, democracy is almost non existent, policing is appealingly violent,...