I would say that no GNU, no FOSS drivers, and a non Maemo5 UI is pretty treacherous too though.
I HATE the disorganized Android based UI experience and I also dislike how weak the CLI is even on LineageOS with busybox installed.
N900/Maemo5 I can do damn near anything up to writing an app using only some quick and dirty scripting; launch it from desktop icon and run it in a terminal window. because of blb drivers though we cant use modern kernels so we have trouble backporting stuff like a usable web browser.

Maemo/linux N series (with drivers exception)empowers users, Android is made to give phone companies power over users.