It is unnecessarily complex for many problems. You can blast away state in many instances. Sure, use it for multithreaded real-time chat, but don’t use it for simple CRUD.

Instead of living the basic react way and gathering state in one component and passing it down as a prop to a child, you feed it into a global "state store". The child component then requests the exact state they need from the state store. This also works reversed, instead of passing "setX" as a function to a child, you just rely on them to gather the state and pass it to the store.

The thought behind this is that components live in pyramids, and state and props ideally only go down and rarely up by setters-> parents and their immediate children can easily share state and props.

This gets more complicated the larger your family line gets. Many grandchildren down, you have since passed the respective props via prop drilling through a lot of components that perhaps don't care for them. It also gets complicated if you want to share state not in an immediate family line, but in a neighborhood.

Overdoing it is almost like hoarding. You think "eh, maybe I need this later somewhere else) and suddenly, your entire application basically lives in the global store.