These days, pretty much all writers need to learn to write Web content.
Yes, even if you’re a Victorian romance author whose readers care more about reticules and spatterdashers than retweets and SEO.
Even if you don’t have your own blog. Any website needs content.
Plus you may want to plan a blog tour to promote your book launch, or guest on a blog for visibility. (Guest blogging is one of the best ways to market your book for free.)
Like it or not, all writers need to become “Web content providers” these days.