You can't find girls that are good enough to be on a par with Pro male players
No Bias but that's serious
Only a small number of players are in pro play , and those players are smart , extremely smart
There aren't Smart girls that can do such a thing , do you know why?
Because a smart Boy is a boy, he wouldn't mind lazily game all the day and spend his whole life gaming
Meanwhile
A Smart Girl actually wouldn't waste her time on a game , she would focus on her life and studying or even working
It's Human's nature difference
Being smart can be gained for some people
So why Wouldn't a girl who already wastes her life on gaming would get smarter and be on a par with those pro players ?
Because girls are more caring and worrying about others , being scared all the time if they did a mistake to make others mad or something
Which leads to make girls more tilt-able and it's the main reason why most of girls are support mains
And , there is also another reason which was already explained to you by the rest of the comments
You can't put bunch of teenagers in a home mixed between boys and girls
Especially of the team was like 4 boys and 1 girl and so on