Most opponents who do not want women and men to receive equal prize money in tennis base their argument on some men having to play longer matches in some tournaments.
I think that all male and female professional tennis tournaments are best of three sets, except for the four Grand Slam tournaments, Davis Cup, and the final of the Olympic Games, in which men play best of five sets.
In the tournaments where men may have to play more sets than women, often men win matches in three sets, and often women win matches in three sets.
Should prize money for the women and men be proportional to the number of points, games or sets that they played in a tournament? Should a player receive less prize money this year because they needed fewer points, games or sets to win than they needed last year? Should champions who were in the easier half of the draw have their prize money reduced? I don't think so.
I think the prize money should be for beating all the opponents that you have to beat, not for how easy or difficult your victories happened to be. On that principle, I think men's and women's prize money should be equal.