What a simplistic, solipsistic, history-blind take! Do you have no knowledge of the 19th century? Arguably, before the Civil War was the prime time of truly "free markets" and pure capitalism in the US. It was also a time of drastic wealth inequality, exploitation of anyone that wasn't a white, male landowner, to say nothing of slavery. How many thousands died creating the railroads in the US? All of those millionaires like Carnegie, JP Morgan, Vanderbilt, Rockerfeller, all made their money on the backs and deaths of poor people.
Prior to FDR and the New Deal, we'd have Panics, where there'd be massive bank failures about every 20-30 years because of unfettered capitalism. And, just like the Great Recession, the rich got richer and the poor got poorer. It was the New Deal and the FDIC that stopped the cycle.
Workers rights are antithetical to capitalism. Triangles Shirtwaist Factory Fire, children in the coal mines in Appalachia, coolie labor building the railroads.
We are not "wealthier, healthier, and happier" because of capitalism. It was the New Deal that helped shape the world the US has now, for which conservativism has been chipping away since Nixon. Socialistic practices like labor unions, collective bargaining, etc., brought wealth and stability, and created the massive middle-class that we have now. There had been no real middle-class before that, historically, just the rich and the poor. FDIC stopped the Panics; labor unions and collective bargaining brought wealth and education the working class, thus elevating and creating the massive middle-class we have now. Prior to the Great Depression, life was pretty awful and hard if you weren't rich in the US.
I'm not shitting on capitalism, but it needs the limitations that socialism brings to keep it in check, to keep it accountable, and not run roughshod over minorities, women, and children.
Also, scientific advancements actually came a lot from war, sad to say. The exponential growth of computers, GPS, obviously nuclear technology, a lot of medicine and medical procedures (thanks MASH units in Korea!) all came out of war. As for later 20th century advancements? All funded by the government. I'd suggest reading Neil DeGrasse Tyson's book, Accessory to War.