Equal pay? This is simply a 'bums in seats' equation, it is entertainment. Not some kind of Machiavelli plan to screw the female athletes out of money. Men's World Cup, the largest sporting event on the planet, Women's World Cup, growing in popularity, but not anywhere near the Men's WC atm. Seems common sense the men get paid more, the economics seems pretty straight forward, more bums in seats, more revenue, larger pot of money.
When Ronda Rousey was big in the UFC she got paid more than the men, why? She was the draw card, she brought in the punters.