Bushings and Air Bags, I have questions

Pretty simple, how do those running bags manage to preserve bushing life? This has always bugged me, I know the Audi All Road runs bags stock, what's the deal there? There is not much deflection in those bushings, and c arms aren't cheap(nor are my Stern arms), and it seems like with bags I'd be replacing c arms every 6 months.

I'm just curious, I doubt I'm going down that road, my PSS9's are great, but with a kiddo on the way in a few weeks, I have contemplated trying out a softer suspension.