By success, assume you mean financial success? There have been several successful self-published authors recently. So, no, you don't have to go through the conventional publishing house.
He wrote his novel in self published chapters on his personal blog. He got a good following, then eventually put it on Kindle at the lowest price permitted, $0.99 - while also leaving it on his own website as a free epub download. He eventually hit the top of the best seller lists at Amazon, got the attention of a publisher, eventually it was also made into a movie.
So if you write really good compelling fiction for instance - well - that's a possible route.
But it's certainly no blueprint for success. For every Andy Weir who succeeded, must be hundreds, more likely thousands, who got nowhere self publishing.
There have been several authors who have achieved financial success as an author just through kindle.
There are also many thousands of kindle authors who are lucky to get one sale of their book every year. So it's no guarantee of success :).
This all depends on what you mean by "success" of course.
I've started self publishing on kindle myself actually, which is why I'm interested in this. But I'm not defining success there as financial success :). Some of my articles are very long, can run to over a hundred pages, and that includes one of my answers here on quora. So, I made them available as kindle booklets, for a small price. They are nearly all available for free online. I was pleasantly surprised to find that anyone at all wants to buy my kindle books as books, when they are available online for free :). For me, this is success, and sufficient reason to make the kindle books, even if I just get a few sales per month into the indefinite future.