I don't think GraphQL is over-hyped at all. Maybe it's flawed, but the design is absolutely on the right traack. GraphQL completely changes how you work with APIs in a front end.
I work on React apps, and by using GraphQL, a component's data requirements can now be entirely declarative. For example, a component can do this (simplified):
{({data, loading, error}) => {
return
{data.posts.map((title, {creator}) =>
{title} by {creator.name}
)}
}}
The component knows what it needs to render, so it declares that. With TypeScript, you can get type-safety
all the way from the backend to the frontend, which means your IDE (e.g. VS Code) can correctly autocomplete, say, "creator." and suggest "name". It's rather magical.
I work on a product called Sanity [1], which evolves GraphQL one step further. It's a Firebase-like data store with schemas and joins, and a structured data model. Without implementing anything on the server end, you can run queries like these:
*[_type == "post" && published] {
title,
creator -> { name },
topPosts: *[creator.id == ^.creator._ref] {
_id, title
} | order(viewCount desc)[0..10],
photos: photo -> {url}
} | order(_createdAt desc)[0..100]
This doesn't just follow a child object (creator), it also joins with an unrelated set of objects (topPosts, which finds the top 10 most viewed posts created by the same user) as well as joining a bunch of 1:1 relations. I'm totally biased, but I think it's a game-changer when it comes to writing web apps, because you can just dump the whole query in a React component, no state management or API writing required.
[1] https://www.sanity.io/