Giving new life to an old eReader using solar power is as optimistic an image of the future as I can get right now. There are dozens of us... DOZENS! Ditto for the build-your-own kit.
I really enjoyed the work you put into finding the best images for the medium. It matters! For instance, I noticed that in the black-white-red ePaper, photos with a subject containing a lot of red hue really pop out. Container and content should always go hand in hand.
https://shkspr.mobi/blog/2020/02/turn-an-old-ereader-into-an...
And
https://shkspr.mobi/blog/2021/09/turning-an-eink-screen-into...