So your approach to the semantic web is to use a proprietary service to bundle proprietary api's that is queried in a language controlled by a single corporate entity and where the resulting data is pretty much never able to be semantically understood by anyone except the api client that constructed the query? A lot of that sounds like the opposite of what the semantic web was supposed to be.
I agree with some of your points here, but I think you might be missing some context in the technologies that are being used to accomplish what OneGraph is doing.
I agree that this example is that of a proprietary API bundling other proprietary APIs, but the technologies they are (likely) using are open source and make it possibly to build self-documenting (via GraphQL introspection) APIs with visualization [1] that can be combined in a modular fashion [2].
If every API was a GraphQL API, there’s no reason you couldn’t easily create a facade that links university course curriculums to, say, associated Wikipedia articles.
Not the semantic web, but it can be a very powerful way to combine data.
