I own a small construction business and wanted to use my drone to take group photos of our crew for our website. That alone required a 107.
However, I mostly wanted to get the training and certification so I could be as professional as possible, regardless of how I was using the drone. That's just me. If there's a certification for something I'm interested in then I want it LOL.
Knowing how to read sectional charts and all the rest that the 107 test requires is really helpful to me. I feel more connected to the airspace, like I belong!