well one reason could be that a lot of code is still written in c and c++ and for example on the TU-Vienna if you study technical mathematics or physics they teach you C and C++ in the first two semesters.
rust and go will still need some time to take a more important role in low level coding and until then they will remain and even after that there will be years of migrations and legacy code left :D .... every language that reaches "industrial standard" is here for a long time ! :)