Concerning the old hardware, it's the most powerful phone which can run latest Linux kernel and the only one recommended by the FSF [3]. Specs is not the whole story in smartphones [4].
[0] https://source.puri.sm/Librem5/community-wiki/-/wikis/Cellul...
[1] https://puri.sm/posts/librem-5-4500mah-battery-upgrade/
[2] https://source.puri.sm/Librem5/community-wiki/-/wikis/Freque...
[3] https://www.fsf.org/givingguide/v11
[4] https://source.puri.sm/Librem5/community-wiki/-/wikis/Freque...