But why do you need so many people?
I came to realize it when I was reading a lot about the pharmaceutical industry years ago. Each new class of drugs it costs about $200 billion over the patent life of those drugs in the class together to do it. So in type II diabetes there is maybe 8 classes of drugs. And through experience and studies they are mainly using 4 of the classes in combination together. And there is a number of new classes that are more advanced coming down the pipeline. So I multiplied it out and 8 classes of drugs * $200 billion in todays dollars = $1.6 trillion dollars.
Now the USA can afford this because spending $40 billion a year in todays dollars since 1980 for diabetes drugs = $1.6 trillion. Then factor in type II diabetes is one albeit big disease area, there are a bunch of other disease areas. The US spent $440 billion for on-patent drugs in the year 2020. Which was 50% of global on-patent drug spending. Since the total US economy in 2020 was around $20 trillion, this was ~2.2% of the US economy. To do this the USA has probably 2 million people working in the pharmaceutical industry.
And then pharmaceuticals are just one part of the economy. As the USA gets bigger in population, more and bigger projects can be underway at the same time. So Hollywood is working on tv shows and movies. Silicon Valley is working on computers research. Detroit is working on automobile research. In each of these areas there is a whole ecosystem including universities, government researchers, mega corporations, subcontractors, small companies, financiers, etc.
In drugs society starts out that we have no known way to help people with that disease. What happens is when you get one drug that is proven to help, it tends to slow down the progression of the disease on average. Although a few people have a remarkable response to that one drug and they actually get better, some even near to full recovery. Then you get a second drug and you add it in and the progression is further slowed down on average, and more people seeing outright improvement. Then a 3rd drug class comes along for that disease and this time its a replacement for one of the other 2, and it is again an improvement.
Eventually you get it so that the average person instead of their disease progressing they are actually improving - but by far most areas of medicine are not that advanced yet.
What happens also with science and technology is improvements in one area, speed up progress in other areas. So computers and software they are starting to speed up progress in pharmaceuticals. So what is happening is the speed of advance is increasing.
The wealth of the country it is an abstraction of what is going on with science and technology. So some shit poor country where they are farming by hand they are poor because their productivity per person is low. And they won't be contributing to developing something like new drugs anytime soon. Luckily for them America lets them copy our drugs for cheap, aka they get the drugs eventually at prices that are set for their incomes. But America we don't have anybody we can copy off of for cheap. We have to pay the huge money to develop it ourselves.