> One thing that supports this view is that there are several Julia packages that are wrappers around existing C/Fortran/C++ libraries That's an understandable

> One thing that supports this view is that there are several Julia packages that are wrappers around existing C/Fortran/C++ libraries That's an understandable misconception. But the reason these packages use C/Fortran libraries is because they're already there, and writing a wrapper is much easier than rewriting the library in Julia. It's not a performance thing, it's a person-hours thing and wanting to use the libraries right now. On the one hand, this means you have binary dependencies and FFI you have to manage. On the other hand, it saves you a lot of niggly optimization work and dealing with edge cases, which the C/Fortran libraries have already gone through and done for you. Once the former starts to outweight the latter and/or more person-hours become available, the libraries start to get ported to be fully in Julia. And the tools available in the ecosystem and the compiler codegen are good enough that there's no artifical performance ceiling due to being in Julia i.e. you do get performance equivalent to being in C or Fortran.