With respect to Clojure, you don't write macros, but many of the really interesting language features within Clojure are built upon macros. (core.async and core.match come to mind). It would be difficult to add them without macros.

I do actually think of my code as a tree/graph structure. Not just in lisps but in other languages as well, I'm always manipulating a stack of trees and thinking about how the data flows through the branches.