At some point my sister had to write a letter of motivation for a job application - a headline and some text, that's all - and she mentioned to me in passing how much money she would have to pay for a Microsoft Word license in order to produce this document.
Obviously I showed her a free alternative, but the fact remain that normal people have absolutely no idea how to use computers. Just being able to open a Markdown file and see the same level of formatting as what we casually drop in this comment section would be groundbreaking for them. Being able to edit it could potentially save them heaps of money.
I suspect this explains why Markdown doesn't work intuitively on most operative systems. There's no money to be made from this degree of user control. Monetizing Markdown is hard as fuck.