Yeah, but that's not what we're talking about here.
RTF has many more features than markdown can reasonably support, even with your personal, custom, syntaxes that no one else knows :/
I use markdown for everything, as much as possible, but in the context of creating a RTF WYSIWYG editor with non-trivial layout & styling needs it's a no go.
Doesn't appear to show any charts on Chrome for mobile...
Seems to be a responsiveness issue, because it goes away in landscape mode, and the charts show.