I'm confused by the documentation, on whether timedatectl set-ntp ONLY enables or disables systemd-timesyncd.service, or if it does this AND other things. Are they interchangeable? I'm betting they aren't interchangeable, because the other systemd services don't have a non-systemctl way to be enabled/disabled (as far as I've ran into.)

Asking, because "timedatectl set-ntp true" fails from the boot cd in arch-chroot with "Failed to create bus connection: No such file or directory". But, systemctl runs without needing a bus connection.