That's part of its appeal, but also a big part of its downfall I think - other languages can utilize a wider "Ascii spectrum" and represent different things in lexically different ways, making it easier to distinguish at a glance.
I like to think you can make a DSL for any situation, but it's not like I've actually done that in practice hah.
I’ve mostly been toying with scheme (guile) and a bit of clojure.
What I think made the language special is its level of abstractness. Unless I am mistaken, it is the first language where you could manipulate function as a first-class citizen. This and the ability to use closure. 60 years ago, it was really innovative.
Now, javascript does it...
That said, people can do awesome stuff with any language, so all this is very subjective IMO.
Some Lisp dialects separate the two further in definitions:
(defun fun (x y z) ...)
The Scheme style is "definition follows use": the definition looks like the call: (define (fun x y z) ...)
Now if the function name above were actually y and not fun, I'd have to spend more than two seconds separating it from the arguments fun, x and z.
That said, SICP is unreasonably excellent :)