If you’re doing rigging, you’re going to be parenting 100% of the time. Joining is more in the modeling stage, when you’re controlling and molding your mesh. Parenting is more of a convenience at the modeling stage, because if you have say a table with glasses on top of it, when you want to move the table to a different position, you don’t want to be moving the table and having the glasses left behind and then having to also move the glasses, you’d want the glass to follow so you don’t have to execute the moving operation more than you need to.
