Is the demand (TV ratings) of ATP tennis higher than WTA tennis? Right now it definitely is but it wasn't always like this in the past, again long before equal pay existed in tennis. It's a man's world after all (blame it on sexual dimorphism in mammals).

And tennis is a sport where you don't get paid if you don't play (assuming that you don't own a big ass contract with a major label). If you want to earn more, you should strive to improve your game and be more successful. And every Top 20 player is a multi-millionaire anyway.
I've always been for a Best of Five final in grand slams for women's singles. Long before equal pay Navratilova was advocating it and I think the Williams sisters were too but it never materialized.
Of course a Best of Five match doesn't automatically translate into higher quality. A 3 set rout can be super boring. But when I think of all the thrilling fifth sets being played...the idea of going through 4-5 hours of tennis would ensure the survival of the fittest in a literal sense.
Yes I know best of Five finals happened at the WTA year's end championships but they are a joke compared to Slams and nowadays even the Men play Best of Three. So this is an odd situation, equal pay exists where it "shouldn't" because of work input but it doesn't exist anywhere else.