the lost days of Maxwell Perkins (editor for F. Scott Fitzgerald, Hemingway, Wolfe, Rawlings, and more) and how he spent years identifying, nurturing and working with promising talent to produce amazing works of literature.
But what you are describing here is actually writing with an uncredited
collaborator (editor, mentor, or whatever) who weighs in after the author has produced something, if raw and unfinished, nevertheless substantial—which is a very different thing from "writing by committee" which is listening to too many suggestions from too many different voices at a point where the author is still extremely unclear about how they wish to proceed at all and has little actually down in writing. These are entirely different things.
Beta-readers tend to be somewhere in between, in that there may be a number of such readers, but these come in relatively late in the process, where the author has completed
at least one draft, and has a fairly clear vision of what they wish to accomplish, even if they are not entirely sure of
how to accomplish it.
Collaborations can be successful. (Whether of the kind where two people sit down to write a story together, or of the sort where the author has input from a editor or other mentor. I am sure we can all think of famous examples.) Beta-readers, likewise can be useful, whether a few writer friends, or members of a formal writing group. (A note on writing groups: there are excellent ones, and there are terrible ones. Most are somewhere in between, because not everyone in any given group is going to be worth listening to.)
But the author who is constantly asking a variety of other people what they should do from the very beginning of a project is asking for confusion and not giving themselves a chance to make their own choices and learn their own lessons and thus to grow as a writer. This is what some of us mean when we say "novels aren't (or shouldn't be) written by committee." As I have said before, if you put your work into the hands of others while it is still too malleable, they will leave their fingerprints all over it. And the result of that can be a smudgy, misshapen mess. Worse, trying too hard to please too many people and follow too many rules can eventually lead to a loss of all joy in the creative process. Not listening to any advice at all, ever, is equally unwise.