Well, not necessarily. What you get with a traditional publisher is use of their platform/audience and marketing.

As a self-publisher, you have to be your own platform and marketing team.

However, self-publishing allows pretty much ANYONE to become a published author. It also allows authors who have been rejected by traditional publishers to get their work out there. I've even read about traditionally-published authors retaining digital rights to their work and self-publishing the ebook on their own or publishing titles that have been rejected by traditional publishers.

Self-publishing isn't new. Print on demand has been around for years, but Amazon really put it in the hands of anyone with their Kindle Direct Publishing platform in 2010-ish.

Since then, other platforms have come out and you can use various services to get your work out on Barnes & Noble, Google Play Books, bookstores, libraries, and more!

It's quite liberating. =)