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.
No, we've been generating it with templates or authoring templates.
Authoring HTML by hand is a very early 2000s thing to do.