What a real publisher does is to market and promote your book in addition to just running the presses. Aka advertising. You're just making the GP's point for them.
A real publisher handles editing, fact-checking, copyediting, layout, cover design, and distribution. As well as marketing, which is distinct from advertising.
Yes, they do also sometimes advertise books, but I don't see how that proves that "anyone with a credit card" can "put out information" of their choosing through a real publisher.
