Learning a bit from different books on writing fiction or non-fiction – or whichever you are concentrating on - from books by successful writers may help you polish up your work to be publishable.
The experience of putting in the effort and hours will also teach you things that no book will.
It is interesting that I learned something (I will not mention it now) in the years of writing creative fiction and reading books by masters like F Scott Fitzgerald, Ernest Hemingway, Harper Lee and Pearl Buck, to name a few.
That aspect of writing that I learned by experience was confirmed by one of the masters. As far as I am concerned, that aspect has never been mentioned in any book on writing, or by any contemporary writer.
And then I realised that the master who confirmed that for me died in 1966, long before I was born.
That is an amazing moment in a working writer – or a creative person, in general.
I mean: You plod on and two or three years later, you read a book that was written long before you were born and it mentions the very aspect you thought should have been mentioned but was never by contemporaries, for reasons unknown.