I guess I just don't see how a WYSIWYG is helping with "web design". For content creators I can see the point, but if you're actually doing design you're not using a WYSIWYG editor.
That's true. But there is a pretty big chasm in complexity between what the majority of web designers are used to using, which is mostly WordPress, and what tools like Hugo do. One gives you graphical feedback instantly, one requires a lot of confusing work before you can even tell something exists.
Designers, by their very nature, are graphical. We are IT people the CLI is our native environment. Designers are the opposite. Hugo might actually be easier for me, rather than harder. But for a traditional designer, it's hard enough to induce panic. Whereas WordPress is just "pick it up and start playing".
Well that's what I mean though. Say you edit a CSS file in the theme you're using for Hugo, if you're using the local server you immediately see those changes. And at least in my experience, most of that is done in the browser first with the browsers developer tools, and then transferred to your source when you get it how you like it.