Different worldviews, new ways to reason about existing issues, raised awareness of other problems, cultures, people. And straight out more knowledge about many things (even if you read only fiction). Overall, you can move forward from a perhaps more simplistic version of the world.
Also, just the increased ability to read and understand stuff should not be underestimated. Many people can read, as in putting letters together to form words, but not read in the sense of understanding anything beyond the most basic of sentences. You’ll get scammed less often. get better deals, etc.