When you self-publish via Draft2Digital, your books can be stocked through Smashwords, Apple Books, Kobo, Amazon (although I publish to KDP directly), Barnes & Noble, etc. My paperbacks are also stocked in Waterstone's because they're published through Ingram via D2D.
After you decide the shops you distribute to, you then have a choice of library apps to distribute to - Hoopla, BorrowBox, Vivlio, CloudLibrary, etc.
Unfortunately, all of them except Hoopla, I think, autoreject erotica, but everything else I publish I make sure to make available in library apps if I can!
I am also more than happy to make eBooks available (in ePub, Mobi, and/or PDF) available to smaller-run trans and queer libraries, like for book clubs, social clubs, etc! They just need to get in touch by email, and I'm always happy to donate books to good causes like that.