It is an evolution in mores that is happening around the world, and nothing specific to the US. China too is evolving towards less "family-affinity" to more mixed socializing.
The US is perhaps a bit faster in evolving because ours is a more "open" society. I can assure you, from what I observe here, that Europe is only half a decade or so behind the US. And in southern Europe, where the role of women advances far more slowly the evolution has also arrived there. (It is fastest in the Scandinavian countries where sexual mores were even more evolved than in the US.)
There are far more women at the heads of companies here in Europe than ever before. Britain had a woman Prime Minister years ago, even if the US has yet to take that step forward in equality of the sexes.
A woman (Angela Merkel) is undisputably the de-facto leader of the Europe Union - simply by her prodigious intelligence she has the capacity to lead whilst others (mostly men) accept to follow. Of course, Germany is Germany, economically the EU's most dynamic economy; which helps Angela enormously in meetings/discussions.
Of course, some countries are more hard-crusted than others. Since WW2 France has been led by a highly singular political group - Right or Left- that graduates from one central university called the Ecole National d'Administration. Meaning this: Imagine that the US were run by those who have a degree from, say, the JFK School of Public Administration at Harvard. The graduates of which tend to see (and debate) complex problems in complex ways that simply do not resolve the original problem. Which leads to stagnation, where decisive leadership is necessary.
The US is an opposite, changing its Executive every years instead of the longer-terms seen in Europe. This has its benefits (new thinking) and its drawbacks (incompetence in leadership) - but the doors are open to all-comers, which is perhaps goodness. Though,
given the present advent of Trump, one has a right to wonder.
Unfortunately, Americans are not faithful voters - the history of voter turnout being much better in other developed countries. For that political fact, see the voter turnout data from the Pew Research Center here:
U.S. voter turnout trails most developed countries.
You will find the US at the bottom ...