Why we need graphql dependency along with client libraray

I have newly started working on the graphql and I was trying to explore the different options available in the market but while going through most of the options i see one thing common that they required graqphl dependency as peer dependency which is going to increase the bundle size of approx 50kb plus the client side library size (total approx 100kb) is there a specific reason why we want to use graphql along with apollo client?