But he didn’t say “scientific computing”. There are not “many other languages” that are used for the stuff that he did describe. Nevertheless, his claim is incorrect. C, C++, Julia, and Fortran are all routinely used for these purposes, sometimes with parts written in assembly. Nothing else, really. The “scientific computing” that people do with Python, Matlab, etc. is not this.

And of these four languages that are successful in this arena, only Fortran and Julia are enjoyable to program in. Between those two, Julia is far more fun and flexible (but brings other drawbacks, of course).