I don’t think you have to approach creative endeavours as hobbies at all. If you chose to approach them as a job, however, then I think you should do exactly that.

If your writing is your business, then how can you justify spending 2-3 years working on a single project with no prior funding and a sales projection of less than 2000 copies priced at whatever a book costs? Imagine if build software startups the way some authors try to become full time writers...

I get it of course. We all know the romantic story of the creative master who only puts out a single master piece per decade, but that’s something you do when you’ve made it. Not when your projected sales are less than 2000 copies.