You, uh, don't like PyTorch and TensorFlow? I can't tell if this is sarcastic.
However my point was that with Julia, those libraries would have been written in Julia.
All the Python libraries that one throws around for these use cases are C, C++ and Fortran libraries, that happen to have Python wrappers.
Any programming language can have wrappers for them, there is nothing written in Python per se.
Python itself is written in C. The Julia github repo shows Julia 68.2%, C 16.3%, C++ 10.4%, Scheme 3.2%. R is a mix of C, C++, R and some Fortran I think...
And how many Python libraries are just plain wrappers, not really written in Python.
I use TensorFlow from .NET ML and C++ API.