Another Kobo user, I have the Clara HD. I like having an eInk device for ease on the eyes, it has a good backlight with a natural light setting for warmer usage at night which is nice.

I suspect most basic ebook readers would be similar. I just wanted something feature-light that was purely for reading.

I did specifically want to avoid Amazon. Basically every other retailer uses the same ebook format: Epub, either DRM free or with Adobe Digital Editions DRM. This means most ereaders can use books from most retailers. The exception is Amazon - they use their own proprietary format with its own DRM to lock you into the Kindle ecosystem. Kindles can now read non-Amazon ebooks but non-Kindles can't read Amazon ones due to this. I find that particularly scummy and want nothing to do with supporting it, especially when most books I buy through Kobo or other sites are completely DRM free by comparison.

(There are ways to get Amazon books you own onto other devices in a pinch if you do some searching. Questionable legality, even if you own the book, which is crazy to me, but it's not impossible. Amazon has been updating their DRM against it, but it's still doable.)