How is society different nowadays versus how it used to be?

From what I read about history it would seem that in the past most people shared at least a baseline agreement on reality. When most are starting from the same basic understanding of what constitutes a decent human existence their goals tend to be aligned even if they had different ideas about how to get there. Now we're in a situation where we're fractured into a bunch of little groups that all have totally different realities, and are willing to fight to the death for their own vision of what they'd like to inflict onto everyone else.