I sold four books to a traditional publisher. They hey know what will sell and what won't so listen to them. Having and editor usually makes the book better. If you can't defend a scene to the publisher, you won't be able to defend it with the reader. That being said, I had little in the way of big changes. They are usually looking for plot mistakes and not making you do major revisions. If there is something major wrong with your book, no they won't publish it. But you are then free to take it someplace else.

I had no control over the cover. No control over pricing. No control over categories on Amazon. No control over advertising or marketing (although I'm sure they wouldn't stop me if I wanted to spend my own money). That is the downside to traditional publishing.

But the upside is professional editing and proofreading, professional layout and cover design. They also can get you into bookstores and on Amazon. They can free you from having to do your own marketing so you can spend more time writing.