As far as being a writer. I have a simpler view (perhaps). Which is similar to sport.
In sport, you have go pro to receive the prize money. And endorsement money.
If you’ve earned money from writing something, surely that makes you a fully fledged pro writer.
If you journal at home and nobody sees it. But you. You’re not a professional writer. Your just a hobbyist or amateur.
I’ve earned more from one 4 minute piece than sone authors I know, have earned in 5 years, from book royalties.