That's not how I understand homoiconicity, "everything is a list" or not has nothing to do with it. The point is that whatever structure the compiler uses to understand the code (slightly loose), is the same code you write, since code is represented as data. But if it's maps, lists, booleans or whatever isn't the important takeaway from that.
In your example, how would I, after the multiplication line but before the result line , manipulate "1 + 1" to read something else like "2 + 1"? In Clojure for example, it would be (+ 1 1) so if you wanna change 1 to 2, you use the typical "replace item in list by index" function, but with Python you're either stuck with AST or "code-as-strings". I think that's where a lot of the complexity and error-proneness gets in.