I'm confused how you got to this interpretation after I listed a bunch of cool languages that (I think) have made many improvements to CL based on CS research.

I'm confused how you got to this interpretation after I listed a bunch of cool languages that (I think) have made many improvements to CL based on CS research. There is only so far you can go with an "everything is mutable -- but you can do anything you want with syntax" model. Common Lisp 2.0 is not Common Lisp, it's lessons learned from Common Lisp plus new ideas rolled into something completely different. Just as an example, Julia's take on CLOS is far more powerful, it preserves compile time macros, and takes SBCL to the cleaners on any benchmark you can find.