I see reMarkable says[1] you can use it without a subscription, but I'm not confident they won't pull the rug under my feet.
[1] https://support.remarkable.com/s/article/Using-reMarkable-wi...
Thanks for mentioning these other devices. I used to have a Kindle Paperwhite (I see it is different than Scribe), butI lost it. I'll explore the other options.