Markdown isn’t really meant to be a universal markup format. Its primary goal is to document conventions of annotating plain text which keep the plaintext semi-consistent and readable.

So the purpose of , * etc is purely emphasis. If you need to represent something specific (bold, italic etc) then that’s a job for the Markdown parser (or embedded HTML etc). The result of the parser (HTML, etc) will be less human readable, but actually able to specify formatting.

I agree that CommonMark could be extended, but I think the focus should be on semantic* relevance rather than markup specification.