For audiobooks you should definitely look into your local library. They usually have a digital offering that includes fairly recent audiobooks. If they support overdrive, you can use Libby, otherwise there’s the Onleihe app.

There’s also https://www.bookbeat.com/de/ which is European and you can do libro.fm. Libro.fm is from the US but you can choose to support a German or European bookstore with your purchases.

Then there are the streamers like Deezer (French) and Spotify (Swedish) though Spotify has some very shady business practices like https://en.m.wikipedia.org/wiki/Controversy_over_fake_artists_on_Spotify

I’m aware that alternatives are scarce and Audible’s exclusivity scheme is making everyone’s lives harder.

Thalia it’s just another locust that should have been prevented merging with Mayersche / Weltbild etc. People seem to have forgotten that it was Thalia that completely destroyed the small bookstores a few years ago, not Amazon.