I don’t think the question of liveness, as Jack frames it, has a 1-size-fits-all kinda answer.
For me, the draw of programming systems that offer more than the normal REPL loop, or compile cycle, is that they empower novel, or deeper understandings of how a program functions.
This can take on so many different forms, and varies depending on the goal and the audience.
I think different sorts of liveliness in a programming system can help to promote different sorts/scales of understanding.
• do you need folks to understand your program from top to bottom?
• are you using the program to communicate data external to the program itself?
• does the program facilitate the creation or processing of something? Is there a representation of the thing being worked on that is more intuitive than whatever the default mode is (JSON, binary data, etc.)