Agreed. If the files are delivered correctly and devs have access to the right tools i.e. Zeplin or Invision Inspect, then I can't see any need for an intermediary. These will automate most of the hard work.
I think Jean's an interactive designer, so perhaps they're talking about designing the way it resizes / animates? Zeplin etc doesn't cover that kind of thing.
Edit: nevermind, they're asking about constructing a design system.
Agreed. If the files are delivered correctly and devs have access to the right tools i.e. Zeplin or Invision Inspect, then I can't see any need for an intermediary. These will automate most of the hard work.
Unless you want the extra work, of course.