If you look at the numbers, the US seems to be doing a lot better than the rest of the world since 68% of children live in two-parent households versus 51% in the rest of the world.

"While U.S. children are more likely than children elsewhere to live in single-parent households, they’re much less likely to live in extended families. In the U.S., 8% of children live with relatives such as aunts and grandparents, compared with 38% of children globally."