Then please show us what would be right. Design a plain text format that satisfies all the countless demands like yours that everyone makes (you’ve got 10 years of forum posts, plus plenty of online blogs to scour). Note that Markdown is used for far more demanding things than a mere “chat message”, from websites, to technical documentation, to doctoral theses. In fact probably the most commonly used lightweight markup tool used by researchers is Pandoc, created by @jgm, who not coincidentally is the author and maintainer of CommonMark. His decision to support lists that start from a number other than 1 wasn’t made lightly.
Or since there is no chance your proposal will be merged into Markdown/CommonMark for the backward compatibility reasons I already stated, and since your irritation has to do with whatever chat software you are using, propose your changes to the makers of that software (and its user community). Let us know how it is received.
Unless your chat software is only used by those 200M, your solution might need to please the nearly 2 billion native speakers of CJK languages, the over 1.5 billion native speakers of South Asian languages, and nearly 1.5 billion people of Africa whose numerous languages have yet their own conventions. And 300+ million native Slavic language speakers. I wonder what set of rules you’ll come up with that avoids a Chinese speaker coming in with criticisms like yours?
I look forward to your technical paper describing your solution and to see how you handle the countless drive-by absolutist criticisms you will get. Assuming you get any response at all.
(To the community: I know it’s foolish to respond to arrogance and ignorance in this way, but I have trouble ignoring people who walk into a complex problem out of the blue and declare that “it’s plain wrong” and “nothing to debate”. In the age of Trump, I’ve found it harder to just stay silent. My apologies for failure to remain silent. I need a )