I use Kindle's, but a while back I purchased a reMarkable 2 tablet (reader, writer, linux-based, open ... etc). I can't think of too many reasons why I'd move away from reMarkable and to a Scribe. The former is more open, as in I can replace the OS on it with one of my own (much GITHUB or other developer activity around this device).
Only a kindle makes you pay more to receive less advertising on the device. Kindles usually have a few proprietary file formats that they can read, vs all that are out there. The last time I checked, the filesystem on a kindle just flat out sucks ... you can't organize all your books the way you want to.
Sometimes, kindle software updates can change the home view on you, so you're lost for awhile. Much is done to drive you to the Amazon way of doing things. Their main file format is encrypted, and I hate encryption, so I spend time "unlocking" the books I buy, then putting it back on the kindle.
I did throw an older kindle into my buried cache box, loaded with enough books to restart civilization ... They are good enough to be buried
But, just as easy to throw an RPi and a usb thumb drive in there with the same stuff.
The "scribing" market is tough on vendors/devices ... much is proprietary and goes the way of the dodo ... reMarkable will buck that trend (I hope). I've already found additional uses for my reMarkable, so getting more use out of it than the vendor intended!