I had the privilege of taking a 10-week course on Hokkien when I lived in Taiwan, and while it is true that Hokkien is unwritten, it is also true that there are some classic poems that are really only intelligible when read in Hokkien. The evolution of Hokkien and how it relates to classic Chinese is utterly fascinating to me. I feel like my understanding of Chinese as a whole became a lot deeper after learning Hokkien.

People say that Hokkien is a dying / dead language, but the way I see it is that it won't die out completely in my lifetime so it's still worth learning.