[blindmute]

> What is react query's role here ?

Its role is to do everything you just said in one package, plus other networking features. It fetches, updates the store, subscribes the components, caches the responses, performantly rerenders. It allows configuration of when to refetch, how to cache, polling, pagination, infinite scroll, etc etc via a simple API.

Nothing is stopping you from writing all this yourself, but libs exist for a reason. It's a terribly useful networking package. If you just use a generic store and write a fetcher yourself, you have to at the very least write logic for when to (re)fetch and for persisting the responses to the store.