What you need to understand is that when you join "the world of self-publishing" you have taken on a second job, you are now a writer and a publisher. Writers write. Publishers publish. You are ignoring your second job.
There is nothing stopping you from writing what you want and and uploading it. Lots of people do that. It's much easier, and much less work. But this is how self-published books have gained a reputation for being of a lesser quality than traditionally published books, a reputation that those of us who want to be taken seriously have been trying to turn around. ... You win some, you lose some.