> There is one huge advantage that i don't believe REST can solve: a GraphQL server returns a schema that tells you exactly what can be queried.

So, commonly, does a REST endpoint that observes HATEOAS (without which it is not REST.)

> I know there are tools like Swagger that solve this problem to some extent, but its not baked into the standard like with GraphQL.

REST is an architectural style, not a standard, but it is baked into the description of the architectural style.