Great quote, though I see here that its source is contested: http://www.thetolkienist.com/2014/01/03/not-a-tolkien-quote-fantasy-is-escapist-and-that-is-its-glory/
I think the beauty of fantasy is that escaping into it frees us to experience new ideas, see new problems, and try out new solutions without the high-stakes pressure and consequences of the real world. By seeing the world as it isn't, we gain perspective on how it is, how it should be, and how we may build bridges between the two.