I think it’s hard to run a game in the Witcher setting but taking out the Witchers - they breath life into it, they’re connected to the history and Conjunction of the Spheres, and there’s a big appeal to players.
One of the things I like about the setting is the thin line between monsters and men. Another thing I like are how monsters and ancient magics are manipulated by rulers who don’t understand what they’re dealing with. Witchers fit those theme well, but they’re not at all exclusive to Witchers.
Btw, thanks for you input, it’s really helpful 