That is not true, there are plenty of non-FOSS packages in extra/multilib (e.g steam, discord, nvidia). The only criteria is if there is an interested packager to maintain it.
>The large number of packages and build scripts in the various Arch Linux repositories offer free and open source software for those who prefer it, as well as proprietary software packages for those who embrace functionality over ideology.
>The large number of packages and build scripts in the various Arch Linux repositories offer free and open source software for those who prefer it, as well as proprietary software packages for those who embrace functionality over ideology.
[1] https://wiki.archlinux.org/title/Arch_Linux
[2] https://wiki.archlinux.org/title/Nonfree_applications_packag...
[3] https://bbs.archlinux.org/viewtopic.php?id=272134
[4] https://bbs.archlinux.org/viewtopic.php?id=273609