Is the `reboot` command safe to use?
The reboot command appears to work differently depending on the distribution.
For example on Ubuntu/Debian and CentOS it shuts down services first while on Arch Linux it reboots immediately (at least with my setup).
Is it always safe to use reboot?
I found a very good explanation here
The BSD halt and reboot commands were low-level, drastic, and immediate. The considerate way to shut down a BSD system was the shutdown command, which did all of the things that one expects to happen: wall messages to users, services gracefully killed, log entries written, logins disabled, and so forth.
It also explains that on the systemd toolset it always shuts down services first like @muru mentioned.