One of the neat things about self publishing in the modern world is that your book stays for sale for as long as you want it to.
With traditional publishing you have a few days to sell a decent amount, or your books will be sent back to the publisher, and you won’t get re-orders, new editions, new contracts, any more money. It’s brutal.
With self publishing, Amazon (and all the others) keep your digital files on hand forever. One of those files can be used to build a physical copy of the book, and the other one can be downloaded an infinite number of times. If I choose, A Long Walk will still be for sale in fifty years. I don’t have to worry about hitting a sales target or else having the book returned.’
The flip side of this is that it’s pretty unlikely my book will end up the shelf of a bookstore. At least unless Amazon randomly decides to feature it somewhere… but the odds are pretty heavily against that.
For me that’s a trade-off I accept.