You don’t write for success. That takes part of your attention away from the writing. If you’re really doing it, that’s all you’re doing; writing.
There’s an unwritten compact between you and the reader. If someone enters a bookstore and sets down hard earned money [energy] for your book, you owe that person some entertainment and as much more as you can give.
An Introduction to Heretics of Dune, Frank Herbert
To bad more writers today don’t take that advice!