Here's why:

* Equilibrium and Catalysts: Catalysts speed up both the forward and reverse reactions equally. They provide an alternative pathway with a lower activation energy, allowing the reaction to reach equilibrium faster. However, they don't change the relative amounts of reactants and products at equilibrium.

* Position of Equilibrium: The position of equilibrium is determined by the relative energies of reactants and products. A catalyst doesn't change these energies; it only affects the rate at which equilibrium is reached.

In summary: A promoter catalyst increases the rate of reaction, but it doesn't shift the equilibrium position.