Your Steam only shows menus without any content. And you cann't open Chat windown as well.
It is known issue with freetype2
, install an update and your Steam will work like a charm.
sudo pacman -U https://archive.archlinux.org/packages/path/freetype2-2.10.4-1-x86_64.pkg.tar.zst
Swith your input method to English while playing game otherwise you cann't move.