Just remember there are lots of browser alternatives, just they are usually also Firefox or Chrome. (Edge is Chrome.)
When Firefox updated their privacy agreements, I moved over to Floorp.
Also, I actually jailbroke my Kindle Paperwhite last night. It was pretty easy. It’s now got a free ebook reader on it (with a different UI) that handles non-Amazon book formats, so I can just plunk epubs on there are read them directly.
Shame it has so little storage space. If it had more, I could put Alpine Linux on it, but this is kinda a bottom of the line one…