I'm from Brazil, and despite nearing my thirties, back home the majority of my friends live with their parents and it is hardly seen as a big deal. I think a big driver of this shift is the fact that in the U.S. it is extremely common for one to leave for college, whereas in Brazil literally 100% of my friends who went to school in the country resided with their parents while they were in school.
One of the things that most attract me about the U.S. is the fact that opportunity and mobility is so rampant, and you have people crossing the country for jobs and a different life. That is a superb thing. But what I never, ever understood is seeing young friends of mine who get jobs in their hometowns but who stubbornly "move out" even if they are barely making enough to survive. In terms of lifetime earnings, those few thousand dollars a month that go to a stranger for rent are so, so valuable.
Another point this statistic does not take into account is that the current generation of "parents" are also on average better off than their parents were. The prospect of "living with the parents" would have seemed worse for my father than it did for me. I get that there are economic forces "forcing" kids to stay home, but I'm sure there is also a genuine shift in preference as well.