Highly nested constructs are more common and natural in Lisp. I think that explains the low level of indentation. It also hurts readability compared to impera

Highly nested constructs are more common and natural in Lisp. I think that explains the low level of indentation. It also hurts readability compared to imperative languages, where it's common to have long sequences like this: do something; do something else; do something else; do something else; do something else; Sequences like that give you long columns of aligned text that make it much easier to judge relative indentation on the screen. Lisp's readability advantage (if it indeed has one; I'm giving it the benefit of the doubt for now) are at the whole-program level. On the function level, it seems more difficult than imperative languages. It would be more fair, and more to the point, to compare it to functional languages. If you write in an imperative style in Lisp, all the parens line up neatly, and it isn't so hard to read. But who codes that way unless they have to?