I won't pretend this is a universal truth, but often code that is quicker and easier to design is quicker and easier to read and understand. A language with less necessary boilerplate can take less reading to understand. Maybe you have a clever IDE that folds away boilerplate code for your chosen language, so that may not always apply.

Lisp originated as an intermediate code. It's basically an s-expression encoding of an AST. There was at one time a frontend planned, but people started writing all sorts of code directly in Lisp.

If your developers don't understand any layers of the stack below their own input, that's a bad thing. Lisp's interpretation or compilation is largely tied more or less directly to the input syntax. It's a language made powerful by the interactions of a handful of first-class concepts being allowed to interact with few artificial limits. Once your developers understand those concepts, it's pretty easily read except perhaps deeply nested constructs.