I don't know why she's nervous, she clearly knew the spec well and didn't have to resort to modern abstraction frameworks to serve a simple static site.
That's not what Moore's law is, that's one of the (former) effects of it. Moore's law is about transistor density, and its increase remains roughly constant.
It's overkill for static sites, but credit should be given to JSX for being a decent way to create DOM nodes dynamicly. You can use a JSX transformer without using React, too.