Im trying to help a friend without having in depht knowledge.
She wants an e book reader (phone is suboptimal) that is not limited to a company and at best supports tumblr which needs a browser like waterfox or an app (i will try to reccomend her wafrn later on)

most foss e book readers i found are a minimalistic linux system that seem to purely support e books
It simply being an e book reader is probably fine but bonus is bonus

Edit: thanks for all the useful answers, i will talk with my friend further about it but i didnt want to bloat the comment section as every comment is very much appreciated.