A part of this, I suspect, is also down to the priority given by the clubs to the development of players during their youth, where there's a significant imbalance.
In my son's team, there are three stand-out players: two boys and one girl. The boys have been signed up by Everton and Liverpool respectively.
Even at a tender age, the boys travel to the academy a minimum of once a week, and you can see the focus these players are receiving from the clubs.
In my humble opinion, the girl is the far better player in pretty much every area (she stands out in matches), but the focus of the clubs is not for young girls.
Physicality is obviously a factor we shouldn't ignore and where many men will have an advantage, however the development of natural ability is a part too.
These boys will likely be given years of support from the clubs, which will develop their game, whereas it's likely she'll receive much less in terms of coaching.
So when we're comparing these international players, we need to consider the ten to twenty years of unequal support and development.
If that imbalance is reduced, I think the standard of the women's game will naturally increase as it's already shown to do.