The Commands for making a USB installer drive yield an invalid device point error in Terminal

What is the name of the mounted volume on the USB stick that will be used for the installer? You need to make sure to provide the correct volume name for the installer or rename your USB stick to "Untitled". Also make sure the USB stick's volume is GUID partition and MacOS Extended (Journaled).

I also recall that the Sierra installer has been broken for a few years (Apple decided to hide it instead of actually making a simple fix to one of the files) when attempting to create a bootable USB installer. I don't recall the command to fix the Sierra installer, but there have been multiple posts on these forums with the command to run to fix it. Actually found it fairly quick:

https://discussions.apple.com/thread/251386184?answerId=252696531022#252696531022

Is there a specific reason you need macOS 10.12 Sierra? If not, then you would be better off installing macOS 10.13 High Sierra. AFAIK, any Mac able to run Sierra can run High Sierra.

How to create a bootable installer for macOS - Apple Support

Sierra macOS 10.12 via Terminal

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled  --applicationpath /Applications/Install\ macOS\ Sierra.app --nointeraction &&say Done

The Untitled in above command is the Name of the External Drive where one what's to make it a Bootable Installer of Sierra macOS 10.12

Actually no but I am very aware of a " More Learned Colleague" who, if finger crossed, they come across your question and offered added insights.

Both @ BDAqua, @ Eau Rouge off the top of my head and a whole host of others