Elchemy creator here. Quite the opposite to be honest. I come from Elixir background. It's just that npm is much more reliable when it comes to global system-wide installations

Are you saying Mix/Hex is unreliable or are you saying npm is on more machines globally?

He's talking about installing a package globally on your system. That's the -g flag

Hex has global commands as well

There's no real advantage in having a global command when the command doesn't make sense outside of a project folder