The Witcher games didn't invent anything. Everything about the Witcher 3 is based upon years of Bioware games. By the way, the first major CD project work was actually a translation of BG into polish, and the first Witcher game uses the NeveeWinter Night's engine.
True, but they are still the best in open world action RPGs there is out there, even if they didn't reinvent the wheel or anything.