Sure, macros are functions that take functions as input, and produce new functions as output. But they take the function's symbols as input and produce a new set of symbols. So a macro can extend the syntax of the language without having to modify the core language system. Anyway, what's unique about Lisp macros vs say, Rust macros, or C style preprocessors, is "homoiconicity". The data structure that a Lisp macro takes as an input, the lisp code, is the same data structure that the language uses normally (S-expressions, lists...), so writing a macro requires few new language skills compared to writing normal lisp (again, compare writing Rust macros, a dark art in comparison).

At the same time, you get a mushy tree as input, instead of a properly typed AST "object" with accessible "function name", "method parameters" everything that you can just refer to.

It will be the third arguments' 2nd arg with s-exprs, following your arbitrary pattern you figured you want to use. So it's very arguable which is easier to use, sure for some "party tricks" lisps will win, for anything more useful my vote would go with rust/Scala macros for sure. So again, you win nothing by homoiconicity, the by-the-compiler implemented parse function is more complex in rust, which is 100% abstracted away.