If the quality of the road is bad, gravel bikes are equally as uncomfortable as race bikes. Not talking about non-asphalted roads as race bikes are of course not made for those.
I'm not talking about comfort, I'm talking about ability to handle the surface properly. Skinny nonsense race bike tires get swallowed up by cracks in the road that reasonable tires just go right over. They're more fragile to debris and simply have less traction on less than ideal surfaces because there's just less tread to work with.
That said the idea that more air cushion space doesn't lead to greater comfort is absurd. A tire that has room to compress doesn't bottom out.
