Even after React became popular, people are still manually typing out HTML elements, although they call it "JSX" instead, but in reality it's just HTML.
My first blog on the internet literally was a bunch of .html files, where my post "template" was the first post copy-pasted when you wanted to make a new post. Changing the design involved changing the same thing across all files.
Typing out <p> for every paragraph is annoying, for sure. But a converter that switches out \r\n\r\n for a new paragraph would be a reasonable middle ground IMO.
Also I often call out my colleagues if they try to put a table in markdown. Markdown is not built for tabular data in most professional settings (i.e., one or two table cell could easily take a whole line of markdown to express). A basic <table><tr><td style="background: red">some number</td></tr></table> goes a long way.
Both. We manually run HTML just fine back in the day.