I 100% agree with you that European women's football doesn't need the US or NWSL anymore. That's true, but those leagues are on a shoestring budget as well.
Arsenal, Chelsea, and PSG have women's clubs and perhaps the men's players on those big squads may help by donating wages to help support the women's organizations. But their Womens Super League competition needs to survive too and Birmingham City and Brighton women's teams may face stiffer challenges. Their men's teams will need revenue and perhaps at the expense of their ladies clubs.
Hell, if anyone is a European club fan and their club has a women's team, buy that jersey to support your club too! = D