Perhaps there could be something in the std-lib that allowed packaging into an executable but with some limitations, as a toy example: only supporting the std-lib dependencies. There is some precedence for minimal implementations existing in std-lib and third party libraries being more capable e.g. simple http server. So something like PyInstaller would be for when you need something more powerful, like support for third party libraries in the toy example limitation.
This could amount to adding certain extra features/behaviour to the zipapp module and a lightweight python_runner app (something like blender_runner for blender)