They probably only have tires because the rules say they have to. I kid, mostly. But at some level of skinny and pressure you might as well have an o-ring.

I find carbon bike parts "stiff and dead," they don't vibrate but they don't absorb that first hit any more than anything else. Also BobbyG's bike is a proper road bike with light and skinny parts that can flex. The fork on my gravel bike is a cargo hauling beast for 3-pack or low rider racks and disc brake so it probably needs that 43mm tire because it's never gonna be "whippy." Which is how you start making the case for suspension forks on gravel bikes... but that's a different thread