REPL-driven development keeps me in the flow. I can write (and test) multiple different approaches to a problem in J or K before I can finish typing the first approach in C++. And that's not even counting time and context switching costs of compiling and running the C++ code.

Lisps and Smalltalk also have repl-oriented development, but they're verbose. Even tab-selecting a Copilot generated autocomplete takes more keystrokes than some array language programs.