Did you know that in 2018 there were more than 1.5 MILLION books self published? Think about that for a moment. Over a million-and-a-half in one year alone. And the number is growing every single year! I think it's fair to say that self publishing is a viable publishing solution.
Nearly 100% of the books you see in Barnes & Noble have been traditionally published. These are books that were produced by an imprint of a publisher such as Penguin Random House, Simon & Schuster, HarperCollins Publishers, Macmillian U.S., or Hachette Book Group.