Speechify is trying, though the catalog isn't nearly as wide

https://speechify.com/audiobooks/

try librivox.org, decent public domain coverage.

Gutenberg has some. Perhaps I need to help by reading the classics out loud... into a microphone... and uploading them.

libro.fm is an option for buying books. You can purchase a subscription or buy individual books. Some of the money goes to support local bookstores, so that's kind of neat. They're also not Amazon, so that's kind of neat, too.

I'm a big fan of the Libby app, which you can acccess through your local library. If your library subscribes to the service (and it's likely they do if you live in the USA), then you just need to log in with your library card. https://libbyapp.com

There's also LibriVox, which is mostly a volunteer project. As its volunteers, the quality of the reading can vary widely, but you can sometimes find audio versions of older literature here that can't be found anywhere else. It's also free.

https://librivox.org/

Just because a library subscribes to libby doesn’t mean you nessesarily get it. My local system does, but they went for cheapest plan that only includes children’s books.

Thankfully my library uses Libby - I just wish they let you check out physical books too like how Overdrive used to.

libro.fm is the website I use for audiobooks. The library is signficantly smaller but it's 100% DRM free, you can support a local bookstore with your purchases [1], and they have a subscription that gives you credits you can spend on audiobooks, very similar to Audible.

[1] https://libro.fm/indies

I use https://audiobookstore.com/.

I'm a fan of downpour.com: no-drm downloadable mp3s, no monthly subscription lock, and a good selection.