I did it once in my life, I published a book that I wrote. Just a collection of short stories, most of which had already appeared on Internet on a web site.
It even had a table of contents. I did it all in self publishing and I still do not know why. I think I just wanted to have a book published somewhere. It was not a hit, did not get a Pulitzer Prize or even a mention in the local newspaper, but it existed even in Amazon for a while. Do not search for it now, because it is no longer there.
For me it just mattered that I did it.