I’m not sure what you mean by that. Those are script languages that are shared by its source code.
Yes, that's why I chose them.
They still need to be compiled.
No - they don't. Sometimes they can be compiled, but when using a "pure" interpreter, there is no compilation step. The source code is read and executed on the fly. https://en.wikipedia.org/wiki/Interpreter_(computing)
"In computing, an interpreter is software that executes source code without first compiling it to machine code."
JIT is actually a kind of middle-ground, where it does compile the source code (or sometimes just the most critical parts of it) for better performance.
Python is traditionally only interpreted AFAIK, but it's nuanced and it's a rabbit hole I can't hop into right now.
So, my basic understanding is that shaders currently use a JIT compilation model: the first time a shader is needed, it is compiled first and then executed. Which obviously causes stutters. If there was a GPU shader-interpreter that could skip the compilation step at the cost of execution speed (but still be faster than fully compiling the shader) then, well, that would be what I mean.