Most US runners are not peaking as runners until their mid to late 20's. They certainly are not competing in Marathons during their scholarship years in college. Post collegiate there are a lot of good 100k+ jobs out there in the US for hard working people or at least the possibility towards working towards that, not so much for people in other areas of the world.
I had a friend from Kenya that couldn't wait to earn enough money, so he didn't have to run anymore. There are exceptions of course with some who enjoy it, but the majority mindset is completely different. For them running can give the possibility of coming out of poverty. Quite the opposite for a Marathoner from the US.
So, I don't think people that run in the US are lazy, they just have different motivations.
Two Olympic Marathon medals 🥱 in Sydney btw. Country of 125 million that is supposedly grinding harder than everyone else and yet has 2 Mickey mouse medals to show for it. Japanese athletes never makes finals in events that you don't sleep through.