Having high quality of life like easy access to childcare, sick leave and vacation time from work, etc., is part of being a rich country, or more precisely, a developed country. So your argument amounts to "rich countries should be rich", which is circular.
If by "rich" you mean GDP per capita as opposed to development, I don't think it's a great metric -- there are plenty of countries with horrible, oppressive regimes that have a high GDP per capita. There are many low- or middle-income countries that I would rather live in than the "rich" UAE or Saudi Arabia, for example.
Also, how are you defining "should" ? Doesn't that imply some capacity for moral reasoning, or at least willpower? The US has neither -- it is not a person and it has no mind of its own. Saying the US "should" do something is like saying a hurricane "should" avoid my house. It'd be nice if it did, but it sounds a bit odd to put it that way.