[petodo]

Kobo readers are infamous for their swelling batteries destroying displays, KIndle has better built quality.

The answer should be Kindle+Calibre combo (Calibre can run even own server) and no need any internet connection in Kindle.

[Sugimot0]

Anecdotally my kobo aura is almost a decade old with 0 issues whatsoever, and it has a removable sd card which made sideloading software and files a breeze. I wish they continued making them that way.