Personally i feel Markdown is a bit overrated. Besides writing online (for which Markdown is clearly the best tool), rich text isn’t bad either.
I’m not saying you should write in MS Word (which is totally “the cockpit of a fighter jet”
). That results in bloat and overwhelming numbers of options. But rich text writing environments like Scrivener (or even TextEdit. Books have been written in TextEdit.) are nice too, and shouldn’t automatically be discarded.