The suspension effect of lower pressures is just like in downhill skiing when you use your legs more effectively as suspension to maintain good ski/snow contact in a turn. I really notice the diff in my corner speed on bike in a bumpy corner with lower tire pressure (let's say 90 95 vs 110) as the bike is more stable and tires maintain good contact, allowing me higher corner speed and a lot more confident of my traction. In the early 90s f1 had active suspension, like us skiing and even on a bike.