Where you will have difficulty with a self-published book: getting reviewed by anyone but bloggers (unless you can pay for a Kirkus review — low end, $425 — and/or a IndieReader review — low end, $250), getting on the shelves of Barnes and Noble (independently owned stores will often take books on consignment; others will read the book, assess its saleability, and decide whether to purchase it for their store), and being taken seriously by Serious Writer peers (the ones for whom traditional publishing is the ONLY validation).
Something to remember is that being traditionally published is no guarantee you’ll make money or even end up in all the Barnes and Nobles. A NYT best-selling author I know doesn’t have a book in B&N, anymore, the last time I looked. Other traditionally published authors still have to keep their day jobs. Most never get reviewed in People, the NYT, or anywhere else. A small percentage end up on national talk shows. Visit your local bookstore and ask yourself how many of those authors you’ve ever heard of, read about, or read, period.
Nonfiction is an easier sell for self-published authors, as someone else said, but fiction can be marketed if you’re proactive. (Note: visibility doesn’t necessarily translate into sales. People still have to be interested in what you’ve written.) I have three self-published novels and one self-published nonfiction work under a pen name. My first self-published novel was on two different regional NPR programs, was featured in the Stars and Stripes newspaper and three or four local papers in different parts of the country (I moved around a lot), was the subject of a few podcast interviews, was bought by two stores (an indie store in Nashville and a Books-a-Million in Clarksville, TN), and got on a local morning TV show. It’s now included in a text book studying traditionally published contemporary war stories that include Fobbit and You Know When The Men are Gone and the movie The Hurt Locker.
My latest self-published novel, which has received less aggressive marketing efforts, was also recently on area NPR and was featured in our mid-sized newspaper (in addition to being the subject of blog interviews).
My self-published nonfiction title got on TV on a couple different local channels.
You can get self-published titles out there by yourself, sans publicist. Not as easily as a publisher can when a marketing team with marketing experience is behind you, but it can be done. I think whether your book is self- or traditionally published, what matters is whether you can generate interest and/or convince those with a wide reach that it’s something they should be writing about or interviewing you about.
I’d still try traditional first (I’m going to try again with my next one, even though I get a little nauseated thinking of all the ways working with an agent and publisher can go horribly bad; see https://www.janefriedman.com/why-publish-traditionally/) and then, if the Publishing Powers don’t see the marketing/money-making value of your book (business is business), release it yourself. If the writing is good and you believe in it, there’s no reason it shouldn’t be available to readers. Musicians bypass labels and record their songs for YouTube; actors write and produce their own material; painters sell their work on sidewalks. Why should writers have to wait for just the right approval before sharing their work?
[And regardless of what some might say about the quality of self-published work, traditional publishers have put out their own share of crap.]