Lisp is very valuable in the concepts which it teaches; expression trees and their inherent parallelism, functions without side-effects, structured data definition, lazy evaluation.

I've been programming for about 30 years, and did a fair bit of scheme, then lisp early on. I no longer use it, and it's not a great modern language for a lot of internet or IO stuff, but as a data transformation language, few are its equal. I still apply what I learned from lisp to write better code in Java, Go, Python. It puts you into a mindset of using composition of simple functions and data structures, which will generally lead to better code in any language.