Trying to escape the Amazon enshittification, I have started to buy ebooks directly from the authors, or from more "reasonable" ebook shops. It's way less convenient, but at least I own those epub files instead of renting them.
I still use a Kindle Oasis, but at least it takes epubs now.
@doppioslash do you have any reference for some of the more reasonable ebook retailers, for when the authors don't sell books themselves?

@ScatteredRay @doppioslash Kobo.com has a lot of books and it lists the type of DRM (including DRM-free) and you can just download the books you have bought

this was the best of the bigger marketplaces I could find (for fiction books at least)

small issues: can't download all at once and each downloaded file has a big ID string as filename so might need to manually rename

no clue about their practices in regards to pricing/monetization in general though