How do you extract symbols from official binary builds of Arch? According to official documentation (https://wiki.archlinux.org/title/Debug_-_Getting_Traces and bug report threads I've seen), Arch lacks both debug packages and symbols bundled with binary packages. As a result, if you want to debug an app crash on Arch, you need to quit the program, recompile the app from source with your makepkg.conf set to !strip, then try to reproduce the bug in your new build.
It seems Firefox has a script at https://github.com/gabrielesvelto/symbol-scrapers/blob/maste..., but I haven't investigated what it does. In any case, this information should be integrated into the Arch Wiki.