I guess these days it is better to compare GitHub Formatted Markdown, a common extension to CommonMark, as opposed to plain CommonMark. It supports code blocks with language hints, tables etc.
Also, I am pretty sure Markdown with metadata (sometimes referred to as "front matter") already exists and is called MultiMarkdown, though presumably not as powerful/useful as what you describe here.
CommonMark also supports code blocks with language hints (using the ```lang... syntax). What Org-mode has, in addition to code blocks with language hints, is inline code with language hints, which neither CommonMark nor GFM support.
tables
I'm horrified that, indeed, CommonMark doesn't have tables, though you're right that most people now just use GFM.
Comments
I guess these days it is better to compare GitHub Formatted Markdown, a common extension to CommonMark, as opposed to plain CommonMark. It supports code blocks with language hints, tables etc. Also, I am pretty sure Markdown with metadata (sometimes referred to as "front matter") already exists and is called MultiMarkdown, though presumably not as powerful/useful as what you describe here.
CommonMark also supports code blocks with language hints (using the ```lang... syntax). What Org-mode has, in addition to code blocks with language hints, is inline code with language hints, which neither CommonMark nor GFM support.
I'm horrified that, indeed, CommonMark doesn't have tables, though you're right that most people now just use GFM.