We both seem to have direct experience of working with a publisher, but I think you are overstating the effort of most publishers these days. Too many books, even from reputable publishers, are of fairly low quality, which as a reader bothers me even more than stuff like this: https://www.flickr.com/photos/markos/49564386913/in/datepost...
Also, I don't see why them taking on a risk of printing upfront should be offloaded on the author through smaller fee.
When either party takes on more risk in a deal they want compensation. This is perfectly understandable.
If an author wants access to the distribution network of a certain publisher, they must pay.
Ever wonder why the biggest authors don’t simply run their own publishing houses? They understand the value provided. And they rarely if ever reach 50% in royalties (I’ve never heard it, in many decades of following professional writing).
What I do find is authors generally have no idea of the value provided. In which case they’re welcome to self publish. But self-publishing rarely results in great sales either.
Both avenues have pros and cons. That said, I’d likely still choose a publisher, since my time is also important, and I’d prefer not having to be average in a dozen skills when I can invest effort at being much better at a few.
Also, I don't see why them taking on a risk of printing upfront should be offloaded on the author through smaller fee.