The internet is filled with publishers that claim they can help you self-publish your book. The majority of them are either ignorant of what self-publishing is, or they're intentionally misleading their clients.
Of the million authors who self-publish a book, a lot of them believe they are self-publishing when in reality, they are not. Self-published books today simplify traditionally printed books annually by a growing margin. You can know more about self publishing companies via https://theindependentyou.com/.
These alleged self-publishing companies rely on the inexperience of eager, first-time writers who dream of getting their books published.
Several online publishers are willing to make the most of new writers by selling extras that are of no or little advantage to the sale and marketing of books.
These greedy publishers earn all their money from you, the author, and may care less how many novels the public buys. They got handsomely paid through your credit card.
In case your self-published book sells well, it's going to have little or nothing to do with the publisher you employed. However, when you need more books, the normal self-publisher will create two to five bucks on each publication you publish.
Most self-publishers do not even require editing, but if you want to have an edit they'll charge you for editing that will not necessarily fulfill modern publishing industry criteria. So, make the choice wisely