Has anyone found a way to use the ebooks without Amazon? Every one I’ve joined has used Libby to access Kindle books and I haven’t found a different way to access the content.

Yeah, definitely think there are use cases for this (look at how popular the xeink X4 has gotten), but a device smaller in most dimensions than modern smartphones isn’t gonna make a good general purpose ereader for many people

Sidephone, key phone, ikko one with the optional keyboard, upcoming clicks communicator, and dumber mini are all modern semi-smart keyboard phones at or below their discounted introductory price for the base model, with similar enough specs in most areas. Most of these are on some sort of privacy AOSP rom too.

And that’s not including all the unihertz, blue fox, and other Chinese phones that would compete

I think machine compatibility plays a huge role, some machines do mostly ‘just work’ while others are a pain. It also definitely requires some tinkering, though mostly on setup or on the first week or two in my experience.

Also, ymmv and a lot of people swear by them but I’ve never had good luck with Ubuntu based distro, they’ve always been super buggy with hard to track fixes for me. I like fedora a lot better and it similarly has decent (though not nearly as extensive) community support for weird bugs, but I know people swear by many things.