A huge proportion of the world was still under direct colonial control after WWII. Like most of Africa, swathes of Asia. Pick a country on a map and look at the date it was granted independence. I can almost guarantee that it will be later than you expected. Post-WWII is not a low point for colonialism.

I would further argue that many of the countries that were granted independence only received the ability to install administrators who were of an indigenous ethnic group. Trade agreements and terms dictated by loans from groups like the international monetary fund still directed a large proportion of domestic and foreign policy. So even though the government of a country may have had a constitution and veneer of democracy it was still operating at the behest of foreign interests (ex. Shell in Nigeria, Firestone in Liberia, Exxonmobil in Indonesia, etc.), who propped up puppet leaders that allowed them to continue to extract resources under the same or similar agreements they enjoyed under colonialism.

Nonsense. The op originally cited things like childhood mortality, water cleanliness, access to doctors. First of all, non-capitalist economies have seen equivalent change. Look at Cuba, more doctors per capita than any other country in the world. Look at China's infant mortality decline from 1950. Second, capitalism has existed for a long time. Look at an era like late 19th century gilded age America. Huge wealth surpluses but they largely went to the holders of capital, not society at large. Workers were violently repressed, living conditions were abhorrent. Social progress was made through worker action and democratic legislation, not through the allocation of capital and investment. Third, capitalism has also sought to dismantle these things. Private equity is buying up hospitals and significantly harming health outcomes for patients. Corporate lobbyists, especially for fossil fuel extraction companies, have been trying to kill environmental protections for years. Attributing capitalism with improvements to our society confuses cause and effect.

I'm not indicting capitalism. My point was that capitalism isn't responsible for the last century of social improvement.

No I'm not. Capital usually refers to the individuals or corporate bodies that control or direct investment. Capital is the anticident to capitalism.

This post is completely absurd. All of these things have happened in spite of capitalism and they've developed simultaneously in non-capitalist states. We (mostly) have access to clean drinking water because of environmental activism that forced companies to stop dumping industrial waste in bodies of water. We have access to healthcare because activists maneuvered politically to ensure it became a right, not a privilege. That's to say nothing of developing capitalist countries that offer none of these privileges to their people. Capitalism didn't give us these things. If you spend any amount of time reading about the history of labor or the development of regulatory bodies, capital has hindered social progress wherever possible to avoid any restrictions or taxation. These things were demanded and fought for by the people they were affecting. Industry and finance are owed none of the credit.