LISP is maybe expressive and composable language but "best" depends on usecase.

From my understanding due to runtime code generation possibility it's hard to "read" (analyse control flow). When code is hard to read then it's also hard to cooperate. That's probably a reason why LISP isn't more popular.

Ruby shares some of these issues due to too much runtime ability. It's maybe nice to use and beautifull from the outside but too messy inside and you can't really rely on it. Kinda like a cheap girl :P

What you know LISP is best for?