In Stage 2, why is the Pressure as it is?

-In the Equation for Stage 2, SO₂ + O₂ ⇌2SO₃, you can Clearly see that the Products has the Least Amount of Moles, so Increasing the Pressure would Shift the Equilibrium Position towards the Products side -However, this is Expensive, and the Equilibrium Position is already on the Right so it isn't Really Needed -So this Process simply is Carried out at Atmospheric Pressure