Never said it was impossible, just difficult. :/
I'd say that TW3 has mostly lived up to the designer's claims though, definitely. Ironically, it feels like far more effort was put into side quests in this game than the main quests. And some of it isn't too much different than other games, but what I think CDPR does well is give quests a bit more meaning and context, even if just through a few extra lines of dialogue. Many quests still amount to "go here and kill thing" from a mechanical standpoint, but giving a little bit more effort into the backstory for the quests goes a long way in making a quest feel more significant.