>"around 2015-17 - Swift could have easily dethroned Python."

NumPy, SciPy, Pandas, and Pytorch are what drove the mass adoption of Python over the last few years. No language feature could touch those libraries. I now know how the C++/Java people felt when JS started taking over. It's a nightmare to watch a joke language (literally; Python being named for Monty Python) become the default simply because of platform limitations.