We started working on the open world stuff in The Witcher 3 quite late in development, John Mamais, studio head at CD Projekt Reds Krakow studio admits. In many ways The Witcher III: Wild Hunt propelled the studio to superstar status among RPG fans. An immersive and huge open-world that pushed the cinematic possibilities of the genre forward with memorable stories, moments, and character development that fully realised the series epic fantasy ambition.
During its development, and as the size and scope of Geralts final adventure took form, the team at CD Projekt Red expanded and grew to accommodate its vision for the game. We did as much as we could, John continues. Compared to The Witcher though, Cyberpunks open world is way f***ing cooler.
Source: N4G PC Cyberpunk 2077 – CD Projekt Red on Creating an Immersive Open World RPG