Knowing a second language can be beneficial as it will open up opportunities in markets that normally wouldn’t be available to you which could be a competitive advantage. Even if it is a small market in your area as well it could be all yours if you are the only one within your professions who has that skill-set.
I know real estate agents usually learn a second language as it can help immensely In building trust when it comes to hiring the person to buy or sell a home. But this is where it got interesting as I saw one example where a real estate agent learned a little Chinese in his spare time. He definitely wasn’t fluent and his conversations were nowhere near even a child who was born and raised speaking the language. But just the fact that he knew a little seemed good enough for many prospective clients.
They didn’t seem to mind the broken grammar but viewed it as a genuine person trying to learn a new culture. That made him more relatable versus everyone else who didn’t know any. Interesting to think about in that regards where you don’t need to be fluent in a language to sell where in some cases it’s more about marketing perception.