Was reading Friends (gosh thats taking me back) tv Companion to seasons 2 and 3. Writing for tv can be a steady job. But you'd need to be based in Hollywood or wherever theres an entertainment capital in your country. Or if you are songwriting, its where the recording studios are.
Most screenwriters, graphic novelists and song writers collaborate with each other, they write in teams. Its also fast turnaround ..you are looking for a hit. Journalists/reporters write every day and have to work to deadlines. Then theres copywriters who are basically ad people.
This is if you want to make money from writing. Its basically hack work. But its a job.
Ghostwriters write other peoples stories, almost all celebrity memoirs have been ghostwritten.
Paperback writers, depending on how your books sell. could churn out a book each month or every 3 months. If its a series, it will be regular and might become so popular you'd need help. Eg Babysitters club, I think got up to over 200 books and so did Sweet Valley High - freelance writers would write the books but theyd be given plot outlines by the author
Diana Gabaldon had a series that was very popular, called Cross Stitch I think but the latest book in her series was written like at least 10 years after he last. I think the same happened with Jane Auel with her prehistoric romances.
You need discipline to write.
A lot of Christian writers esp pastors, theologists do a lot of research for their books. Its not just something they pop off the top of their head, and they fact check everything. Even if its presented as novel (i.e fiction) the details need to be correct. However they are not limited in their imagination.
Thats the thing with telling a story. Jesus always told parables, and they were fiction but they had a message - a spiritual truth. He spoke to people in parables, those who got them understood, those who didnt just thought he was nuts.