Why isn't a stronger incentive for running a full node built into Bitcoin like it is for miners?

Obviously miners have a strong incentive to do what they do, but another hugely important thing to decentralization is just having a fuck ton of nodes run by a diverse group of people in different geographic locations.

Other than the privacy and validating your own transactions there is little incentive to run a node at all other than just wanting to pitch in and help decentralize. I'm curious if I am missing something and if there's more incentive/motive for running a full node other than that.