Paper production replants trees. Its not saviving any forrests. I would argue the enviromental toll from kindles and cellphones is magnatudes worse.

Any of those has non trivial impacts.

Your claim is valid, but we should take into account that cutting trees and planting new ones is not the same a leaving the trees alone in term of ecosystem. Just like burning down an old town an rebuilding a new one is not neutral in term of things lost.

You'd have to consider how long somebody uses a Kindle and how many books they would have bought to really start to make this comparison, I'd think.