> Of course you can build these elements into your own implementation, but there is value in a higher level standard that has these items guaranteed.
That's what OpenAPI is. (You mention the Swagger tool, but claim it's not baked into “the standard” the way GraphQL is; as well as a tool, Swagger was also the name of the standard, though the current version of that standard is called OpenAPI.)
It is also what JSON:API is.
It is also what OData is.
It is also what RAML is.
Heck, there's a good argument that it is what GraphQL is, too: https://hasura.io/blog/rest-view-of-graphql/