To me, simulation is (mostly) creation/use of a systematically-driven model of something.
The thing being simulated may not have much to do with the real world, so simulation does not equal realism, or even verisimilitude.
Genre emulation does not, to me, equate to simulation, because 1) Fictional genre is not a well-defined "thing" to simulate. 2) Fictional genre emulation is often best achieved by including non-systematic techniques.
These days, I don't really have desire for a lot of simulation in my ttRPG play. I find, again, for me, simulation play puts focus on the thing being simulated, rather than the players, and whether I am running or playing a game, I prefer my ttRPGplay to be more player-focused. I can, and do, play other kinds of games when I want to play with simulations.