Don’t throw away your Kindle, Jailbreak it and take back ownership. Make your Kindle even better with KoReader and other apps. If you wanna see whats possible i recomment this Yt video. If you wanna get started here are all instructions: https://kindlemodding.org/ Don’t let it scare you it seems complicated but its just a lot of (easy) steps. So definitely possible in <2h.
You’re correct. Root is different from jailbreak. Root allows for a replacement of even the OS itself. Jailbreak allows you to install software that modifies low level parts of the system without replacing the system itself. This is as far as I understand it. That’s why this is called a jailbreak, not root.