I thought it was in effect fetching remote code, from git or wherever, and then executing it (or loading it) in the local environment.

I'm just curious to understand the situation better, but which part architecturally strictly needs the JVM? Even with babashka, or on this website, I don't think anything stops me from Frankensteining in an external library in a running REPL. I could technically fetch the content of a library's repo and then copy each file and run its contents (with the ns blocks) in the REPL. Then the library would become locally available (assuming it's a very plain Clojure library that is)

I assume `add-libs` is sort of a convenience wrapper for the same idea