They're referring to a specific bit of code in that Eureka repo that sets innerHtml = "" and then does .appendChild(). They just apparently didn't notice that the code doesn't use React at all (and is meant to demonstrate the use of vanilla modern JS without React).

Yep that’s what I was alluding to as well. I’m pretty sure they noticed it wasn’t using react.

The comment was a reference to the fact that if you don’t use a framework, you’ll end up a building one anyway.