My hot take is that all games are simulations to some extent. Many sports are a kind of war game, simulating a specific aspect of real war, obviously abstracting quite a bit. A big part of the fun in catan is in the tension of having to cooperate with rivals to mutually beneficial ends, much like what happens in economics all the time. The point being, that yes, there are varying levels of realism, but in the end I don’t really think there is a simple line denoting “game” or “simulation.”