IMO react is a special case... I think what that line is trying to convey is that you shouldn't be doing things like adding a script tag that goes in and sets

IMO react is a special case... I think what that line is trying to convey is that you shouldn't be doing things like adding a script tag that goes in and sets all classes to have "background-color: red", and to try to avoid using JS for animations/transitions where possible. Just like when someone says don't HTML and JS, they aren't talking about JSX most of the time.