Well there's gonna be people writing code who can't do it in say a high performance C/C++ setup. Not professional programmers, but professional <some finance discipline>.
Sometimes it will be worth the tradeoff to put that person and a programmer together to code up a solution in another language. Sometimes it will be worth it to have the non-programmer write it in Python and then do Herculean things in the background to make it fast enough.
The gulf between high performance C/C++ and Python is vast and includes most other programming languages, many of which are friendly to write or can be made friendly to write for a limited domain, with significantly less rocket science needed than making python faster.
> Sometimes it will be worth it to have the non-programmer write it in Python and then do Herculean things in the background to make it fast enough.
Nim exists, Crystal exists
It would not surprise me if some shops end up using less common languages to fill a niche (or hell, invent their own DSL).
But it also wouldn't surprise me if a lot of shops land on python because that's what their hiring pool knows.
With insignificant ecosystems, compared to Python.