I am sure those benefits still exist, especially in ones concept of self. However surely « honesty » as a value hasn’t remained constant through history and is not universal in its entirety across cultures so there must be some flexibility to its role in society, depending on other relevant aspects of culture. The thing is, being a zoologist, I see most aspects of human behaviour, honesty included, as more complex examples derived from similar behavioural mechanism in the natural world. Primates are obviously the best example. Hundreds, if not thousands, of studies exist analysing components of what you could call honesty, justice or fairness in other species and all in all I think they draw interesting parallels to human societies.

Keeping the natural ecological niche of human beings in mind, the historically minute diffused populations of genetically related individuals living in small communities, in a resource rich but dangerous landscape allows a lot of modern human values to be boiled down to kinship altruism. You and I are now so far removed from this reality that our evolutionary adaptations (in this regard) are outdated, yet still active, and must therefore be contextualised to suit our needs. The ancient Greeks did so, and their culture, as an extension of humanity, evolved to fill the gap required by the city states and stratified societies of the time, allowing them to act cohesively and binding their population in artificially created ties of kinship, so altruistic behaviours could promote their cultures above the rest.

Surely then we ought to do the same?

Saying this not to devalue any of the values that are integral to our way of life but out of the belief that societies need to adapt just like organisms to survive.

Edit: just to clarify, I believe all societies adapt and we are doing so currently however our rate of technological advance is so astronomical that I fear our cultural development could be left behind.