Clojure's immutable HAMTs are still a superpower nearly 20 years later. They've been copied in pretty much every language as a library (I did so myself in Zig) but what really makes it work well in Clojure is the fact that they're built into the language, so the entire ecosystem is built around them. Libraries that were made independently usually fit together like a glove because they are all just maps/vectors in -> maps/vectors out.
Yeah. I do wish there was something that was like Clojure with a TypeScript or Go-like nominal typing, but I do feel myself missing types a lot less with Clojure compared to other languages.
Yeah, they are so underappreciated - the practical differences in designing, delivering and maintaining software are real. Initially you see small differences "What's the point? I can write that in Python too... maybe it's not as delightful, but who cares?...", etc. Yet over time small annoyances accumulate and become an endless stream of headaches. I see it over and over again - I work on a team where we have codebases in different languages, and some services written in Clojure. Immutability by default is a game of a different league.
"The value of values". Indeed. Q.e.d. No notes.
[1] https://en.wikipedia.org/wiki/Game_Oriented_Assembly_Lisp
https://en.wikipedia.org/wiki/Hash_array_mapped_trie
(The acronym is expanded in the article, but a ways down.)