Python is growing because it's a good scripting language, and there's a need in the ML community for a standard language to write scripts in. The ML community is growing like crazy, thus Python grows. Even though Python is secretly calling Fortran for scipy, or Tensorflow (C++), or PyTorch (also C++), all of which would make good candidates for Rust replacements. So obviously speed is necessary to enable what people are doing in Python.

I make the distinction between script and what we software engineers do, because I had the misfortune of spending half a decade in research doing ML, and those guys are not writing production programs. They're hacking out Jupyter notebooks and writing precariously balanced code that barely works.

That doesn't make Python suitable for large applications. It doesn't diminish the fact that CUDA is growing, SGX is growing, embedded is growing, that we're now unlocking 100G fiber, that we've reached the limits of single core performance, that intel is rolling out 8+ core consumer CPUs. Python is not going to shine for any of these things, but Rust will.