(replying to a complaint about HTML Email)
Personally I think something like basic* Markdown would have worked out better: just enough formatting to be useful, while still keeping it fully responsive to different displays, safer to include in web apps, easy on bandwidth and human-readable in text-only clients.
A lot of that syntax was around as informal conventions in newsgroups and plaintext email, and we would’ve been better off if it had been standardized instead of just plugging in the full web renderer. Though that’s still better than Outlook using Word to render formatted mail.
* Inline formatting, headings, quotes, maaaaybe links. Not any of the extended syntax for tables or anything that introduces layout or breaks readability.