Actually cognitive abilities are improved by gaming. And a high KD aa a result of measured practice and improvement will give your child valuable tools that they can use to tackle difficult tasks outside of games.

Playing music is not any better than playing games for your brain.

I do both, gaming has given me many more tools to be good academically (feeds curiosity, reinforces discipline, great brain excersice) while music has given me an artistic outlet. It has allowed me to express myself, relate to others, and earn social status.

If we focus only in cognition though, games do more.