Please read Barbara Kingsolver! She is a spiritual successor to Steinbeck because she writes about how individuals interact with social systems in a way that shares a similar mentality.
For example, The Poisonwood Bible is about a missionary family that moves to the Congo in the 1960s. The patriarch of the family has so much in common with East of Eden's Cathy: they're written as objectively "evil" characters, but the authors find deep sympathy for them anyways. I love how both Kingsolver and Steinbeck create moral worlds that are comfortable with calling characters out while also exploring shades of gray.
If you want to get into Kingsolver, The Poisonwood Bible and Demon Copperhead are the best places to start. I'll also give a wildcard recommendation to Animal, Vegetable, Miracle, which is a nonfiction memoir about eating locally as a modern way to live off the land.
by caseyjosephine