In the US, soccer was seen as a bit of a girls sport (similar to volleyball or gymnastics, there's guy versions), or at the very least equal-gender.

Compare that to the idea of women in football or baseball or even basketball. In 2010, the WNBA ran a series of ads "Basketball is basketball" trying to convince viewers that women's basketball is basically the same as men's basketball.
https://www.youtube.com/watch?v=6-1P83-YThk

You'd never see soccer have to do that, to try to explicitly argue it's the same sport. But that's how women's soccer was long viewed in Europe, like many Americans view women's basketball or women's rugby - a fine activity, but not worth anywhere near the same investment or attention as the men's version.

But then the Americans started winning in women's soccer. Which was a bit of an affront to Europeans, given the respective importance of soccer in each area. It's be how Americans feel if women's basketball started regularly losing to other countries. And that spurred a lot of emphasis on growing the women's game in Europe and elsewhere and has slowly eaten into the US advantage there.