That's what I think. I doubt a few extra microns of paint will make much if any difference. It won't stop scratches, but might reduce the number of scratches or chips that reveal the undercoat.
I got my bonnet repainted under warranty because the paint was deemed too thin and I have gained 2 chips in the last few months vs the 10+ chips in the first few months, so I think it does make a difference.
However, I think the state of the roads and especially the chippings they use a lot these days contributes a lot. All my cars recently seem to have picked up more than their fair share of stone chips.
What really got me was the huge chip I got in my side panel from the truck delivering the chipping doing 60mph on the newly laid stuff