I think Tolkien was deliberate in not revealing how complex his world was. He told the story… and even then people complain about the amount of exposition. If it were any more detailed you would be overwhelmed.
What’s interesting is how he relied on linguistics and metaphor in literature to add layers. How the story of Aragorn is much like the story of The Wanderer. The cultural differences between Rohan and Gondor is in their language and architecture. Tolkien could have spelled it out for us but he didn’t. It wasn’t until Christopher started releasing the Silmarillion and supplementary backlog of stories that we get to see how deep Tolkien went and how little we actually saw.