No, I do not want or need a middleman whose only job is to pass my data through to another API. It's a huge security risk and potentially a violation of my and my user's privacy. Pretending everything is perfect, it's still another point of failure. Your API service could become unavailable. Your API service could simply wrap others in a huge library and still that means some of them are going to be outdated.

There is no strong reason to do this unless you are binding these services together to create a new platform, like what game engines typically do. They take a rendering library, physics engine, etc., tie them all together with an implementation, and allow you to build the higher-level stuff. If that's your idea but for web development or something then I could see the use but just "everything goes in this monolithic API" is not only a terrible idea, it's a dangerous one.