There are quite a few female Grandmasters I could..... find a use for.
Grand Masters are useful for something other then chess?

Disregarding the obvious troll attempt from the OP.
Yeah, it turns out chess is more than your average shitty board game. It actually takes time and effort to be good at it. Much more than "just a big brain" these types of ignorant questions assume it to be. Even though most people who associate being good with being smart probably think it's a compliment.
It turns out GMs had to put in work, and develop some very specific skills over a long time.
Same sort of crap when people ask if they can be GM in a year.
Grand Masters are useful for something other then chess?
For a start, many of them are better at English than you.
"But could they do something useful with their mental ability, that can just solve some of world problems.
Better they invest their time on something useful, or may be they are just good in chess."
Some strong chess players have had careers outside of chess. Euwe taught mathematics and computer science and Vladimir Malakhov used to work as a nuclear physicist.
Grand Masters are masters of chess, so respected all over the world.
But could they do something useful with their mental ability, that can just solve some of world problems.
Better they invest their time on something useful, or may be they are just good in chess. That they achieve by constantly playing the boring game for hours.
Thanks