The n1x branch merges a skip of 32-bit graphics drivers
Pull request 14453 merges into the n1x branch a skip of the 32-bit graphics-driver step. The pull request says that step was stopping Steam and other game installers on 64-bit ARM.
The script asked for lib32-nvidia-utils on the N1x. The pull request says no 64-bit ARM repository has that package, so the Steam installer stopped before installing anything. Heroic, Lutris, and Battle.net installers call the same step.
The merged script skips that step unless the machine is x86_64. A comment in that file says 32-bit drivers come from Arch's multilib repository, which exists only on x86_64. The comment says 64-bit ARM uses Valve's native arm64 Steam client.
ryanrhughes opened the pull request and merged it into n1x. The pull request says the Steam installer was tested on the N1x.