We can all dream
I don't think that publishers have insinuated themselves though. For many years they provided services that writers could not afford to provide for themselves.
Primarily IMO the actual production of the physical books in enough quantity to make a profit. What author could buy their own presses, bind their own books, without spending a lot more money on equipment alone than they could hope to realize on even 20 books. Then there is the cost of employees to operate the presses etc.
Publishers evolved from printers and bookbinders by providing other services like editing, distribution, publicity etc. and eventually became a controlling force. But I don't see that as insinuating themselves, just a common business practice such as that provided by stores, dairys, and most merchants/manufacturers.
A frozen food manufacturer buys meat/vegetables from a farmer or consortium of farmers, processes it, squishes it out in small uniform portions onto plastic trays, encloses it in a fancy cardboard box and sells it a hell of a lot more than the farmer gets. How is this measurably different?
I know ebooks cost less to produce, but if we had epotatoes and echicken, would you expect someone to cook it up, make it look nice and distribute it at cost or less?