I think you might be missing the main "aha!" of clojure REPLs vs REPLs in non-homoiconic languages: you can very easily execute small parts of the program you're editing without re-typing the code.

In emacs, for instance, you often use `eval-last-sexp`, by default bound to C-x C-e. This lets you move your cursor to a particular point in the file, often deep in a function, and get the results of just the form(s) you're pointing at.

This is a superpower! It lets you test small pieces of your code without writing any test harnesses or scaffolding. Try it with an editor that embeds the repl and has these commands, and you'll never want to develop any other way.

It does cause you to want to structure your code in 'repl-friendly' ways, so that you can, say, restart your main server or reset your state without restarting the whole process.