nheko is unmaintained and just a bad matrix client. there are better clients out there, such as quickmedia (quickmedia-git in the AUR)
it doesn't have encryption yet but it's work in progress. for now, you can install and set up pantalaimon to get encryption working if you need it.
then there is gomuks, a CLI matrix client. its a little buggy and laggy, but not as bad as element.
quickmedia has vim-like keybinds and is written in C++, and fully free software of course.
it doesnt just support matrix, but also other web things that would involve JS in most cases, like youtube, peertube, lbry, manga sites, 4chan, soundcloud, etc...
it's not using any toolkit like GTK or Qt, but instead uses X11 and openGL directly, which makes it extremely fast and lightweight even on very old hardware.
i talked to it's developer about throwing it into the parabola repos, and he said he would like it if he has control over it because it constantly gets updates, to keep it working with rolling release arch packages, since parabola repo packages aren't updates as quickly as arch repos or the AUR.