I don't want to be a gatekeeper, but Clojure, Janet and similars doesn't even have cons cells; that's hardly 'the same programming language'.

I would call these different dialects of Lisp. The data doesn’t have to be a function. It’s illustrative. The patterns of application still work. What’s the difference if delimiters are different or if you are calling JVM libraries? The high-level ideas are still right there. Consider JavaScript. It is definitely not a Lisp, but if you model it as Lisp in C’s clothes, then all of a sudden IIFEs make total sense. The point is that it’s a helpful mental model for languages other than Lisp.

Is the lack of cons cells a significant limitation?