What are the potential drawbacks of majoring in journalism or creative writing if your goal is to become a book author?

It is statistically more likely to get published in nonfiction. That makes journalism a good career for a nonfiction author.

Often journalist's articles can provide a source of content to create a book. The big issue is being self directed enough to choose content line that meets your interests in writing a book. Journalists don't always get to choose their assignments. Many have to work their way up from the ground. However book topics are extremely wide range in nonfiction from food, religion, society, arts, politics, science, literature, geography, travel, you name it.

The main drawback is that writing news can be very high paced and demanding, making it hard to ever have the timebor desire to write a book.

Creative writing writers can also publish in nonfiction , their experience in fiction techniques can expand into memoir, essays, spirituality etc. They can also get work writing articles, but journalists have a better introduction to news writing and the need to write the story as it happens.

Creative writing careers tend to be in editing, acting as an agent, as well as writing fiction books. They can write reviews, blogs, short stories, poetry, etc.

Tge main drawback for creative writers is that writing fiction seldom pays as well as nonfiction.

The pay can be better based on your focus, on your ability to draw an audience, a desire to learn from your peers, and perseverance in your desire to write what you must.

Either degree will likely help.