Sure, the libs are mostly written in C/C++, but all of them have first-class support for Python and oftentimes Python only. Serving the model is a different story and you can use whatever language to do so.

As someone who has worked in the DS realm for an extended period of time, I can tell you Python has practically zero competition when it comes to data wrangling and training models. There are plenty of contenders when it comes to serving the models or building “agents.”

As for type checking, yeah, it sucks big time. TS is a much better type system than the bolted-on hints in Python. But it’s still JS at the end of the day. All the power of V8, a zillion other runtimes, and TS gets marred by a terribly designed language.