Absolutely agreed.
Though, I don't know if I'd agree that it can all be attributed to being open world. Some of that is purely the effect of negligent and simplistic writing.
We know the main writer from TW2 left during the project to go to Cyberpunk. While there was some rather poor stuff before, alot of this could have been salvaged (along with characters like Saskia, Adda ect showing up) in act 3. As it is now, act 3 is a mess of poor writing and OOC to the max on many characters. When the only thing fans can fully agree that was consistent was Geralt himself and being his best version, says alot.
HoS showed that CDP CAN still do it with characters like Gaunter and Olgierd being two of the best characters they have ever done along with a main story that tops the base game in very way and on par with TW2.