Running Magento commands are the correct user is a must, running as the wrong user can leave your site in a very broken state, and it's not always easy to rectify.
Once you have SSH'd into your site and changed directory to the Magento web root
The best way to work out the correct user is to run
ls -lath pub/index.php
This will output something like
-rw-r--r-- 1 magento magento 1.3K Sep 9 09:46 pub/index.php
Here we can see the owner and group is "magento"
If these two are different, you probably want to use the first one "owner"
If you are using MDOQ managed Magento hosting, then you you don't need to worry about this. The infrastructure is already setup to force you to be the correct user.