Writing well can be helpful in a rather wide range of careers. As one example I majored in math, and found writing well to be a major benefit in my career, and a benefit that became more important as I got more experienced. As a very rough approximation, when young I was trying to figure out how to get stuff to work. When I was older I was also writing about how to get stuff to work. There are a wide variety of specifications of various kinds that need to be written. As another example, people who write scientific papers generally need to be an expert on whatever narrow area they are writing about, but it is best if they can also write well (and often there is at least one co-author on each paper who does write well). I am not as clear regarding what needs to be written in the area of finance, but my guess is that this will come up.
However, that does not mean that you necessarily need to double major. Just taking the appropriate classes and/or getting the appropriate writing experience can often be enough.
One thing that I forgot to mention in my previous post: You can’t live your life comparing yourself to others. There are a lot of people who are very smart and/or hardworking and/or ambitious, and the further you get in your education the more of them you are going to meet. This is good. This gives you people to learn from and strong coworkers to cooperate with. However, you can’t be trying to be better than everyone else. Just be the best you that you can be. Whatever you are good at, do it and do it well. Be responsible and kind. Things will work out.