Thanks for the correction. I would also like to add that /root is probably also something that should be encrypted, you won’t have to shred your root account’s bash_history after accidentally typing your password into the root shell.
I didn’t clarify this in the original comment but imo unless your distro specifically offers the option to partition a drive the way I described it, it’s not worth it. (as far as I know, no distro offers this kind of encryption)