for me the rewards to learning (basic) German have been more personal than professional - attempting to speak with a German speaker in their native language generally makes it easier to bond with them.
Yeah that's completely reasonable, but there are a lot of people trying to sell you on career success that is a mirage. And it can be frustrating the people you want to talk with often speak English better than you speak the language you're learning, though that's more of a problem with some languages than others.