python is not build for speed
Yes, but it scales to speed, letting you speed up your code easily when you need it. Consider Cython and Nuitka. Consider GraalPython. Consider... consider that C dylibs can be loaded and used from within Python without any wrappers.
You can create the <- operator in existing plus by overriding __lt__ and the unary negative sign. Same goes for <~.
Perhaps you should propose an unary postfix - operator. That would let you create the -> operator in user space.