Use-case: Python with Cython vs. C++ [closed]

I was playing with high-performance Python and came across Cython and its friends. It looks like a perfect solution - getting the best of both worlds - Python's easy for humans, and C++ and C's speed.

Also, modern C++ is somewhat more similar to Python, which I see as a sign that Python is good for humans.

If Python could be as fast as C with the help of Cython and friends, what's the reason to use C++ anymore? Could you name some use-cases that C++ still does better? And, when is C++ the only choice?