Perhaps you might consider the Freewrite https://getfreewrite.com
As long as it has an internet connection, it backs up to the device's own cloud. And, it also backs up to Dropbox, Google Drive, or Evernote. Or, when you're done for the day, you can hit a key to email the work to a preset address. And, as a final redundancy, you could always plug in a USB-C cable to copy the data off the device as if it were a thumb drive.
It is a bit expensive. And, you can't edit. All you can do is draft, ignoring any mistakes. You can do editing on Obsidian.
Omgosh. I have to have one! 👀
Out of my league right now financially. I\m rebuilding after a hectic life challenge and massive subsequent shift.
But what a brilliant concept and creation.
Thanks for sharing this :)