I disagree with you. Men are bigger and with stronger bodies than women. This is indisputable.

For example in tennis, the Williams sisters are probably the best. Did you know they played against the man ranked 203 and neither sister stood a chance? Again, this guy was the 203 player!

You can read more on this article http://www.marca.com/en/more-sports/2017/06/27/595296da468aeb99218b464c.html

Another issue would be, for example in football, you know sometimes there are impacts, a few days ago a player in England broke his leg! And today CR7 ended up with blood in his face.

So, imagine a football game where a man goes strong against a woman and really hurt her (not because she might be weaker, but because of the natural impact of the game)... well if this happens I am sure the whole world will start to bombard this man because he wasn’t gentle or whatever with the woman. So men would play with fear of hurting the women. This fear doesn’t exists when it’s men vs men.

Perhaps in the future, if we manage to have synthetic bodies, then there would really be no difference. But for now, there is.