There are 2 distinct pots of money that are being talked about, but most people don't know the difference.
The first is the amount of money in the FIFA prize pool. The men's tournament in Russia last year had a total prize pool of $400 million for 32 teams. The women's tournament this year had a total prize pool of $30 million for 24 teams. That's literally an order of magnitude difference on a per team basis ($12.5m v $1.25m). There were reports last week that FIFA wanted to double the prize pool for the next WWC ($60m) while also adding another $40m to the men's pool for 2022. Doubling the pool sounds great until you realize that leaves them even further behind because the men had an extra $10 million added.
If you combine this with all the other things FIFA has done over the years (forcing the 2015 WWC to be played on turf as an experiment, president of FIFA suggesting the women should wear shorter shorts to get bigger ratings, 24 team WC while the men are expanding to 48 soon, letting the men's Gold Cup and Copa America finals be scheduled on the same day as the WWC final just to name a few), it is fairly obvious that FIFA isn't treating the women's game even close to an equal. I saw a soccer writer tweet that the finals stadium was completely out of tournament gear before kickoff because FIFA didn't order enough. There were other reports that games in the tournament wan out of gear/beer, so it is actually hard to know how much the WWC could generate because FIFA is leaving money on the table because they just don't care.
The second pot of money is the one the USWNT players can actually influence the most- the money coming from US Soccer Federation. In general, the women are paid less on a per game basis compared to the men for appearances with the national team, but the women play more national team games. A lot of that is because the club game is where the men really make their money, but the national team is a way for women's players to make money to supplement pretty low club wages. Another wrinkle in this discussion is USSF currently still
subsidizes some top player salaries in the women's league (NWSL) while they don't for the men (MLS). In general, the men are treated better than the women by USSF, but the differences aren't as stark as what FIFA has done. I think we'll see a big change in things during the next round of CBA negotiations, but some things won't change until there is a dramatic shift within the internal governance of USSF.