I think the main reason we aren't moving away from C and C++ is interopability, and not performance. I can come up with a number of benefits of C in this regard

I think the main reason we aren't moving away from C and C++ is interopability, and not performance. I can come up with a number of benefits of C in this regard: 1) Ability to use existing libraries directly (just #include and add to LDFLAGS). 2) Ability to be called (as a library) by code written in almost any language, without indirection through serializing function calls or similar. 3) Modern operating systems can share code and constant data sections between processes for normal compiled programs (but not byte-compiled ones). 4) C has a good tool support, such as debuggers and packaging tools for Linux distributions. 5) A practice of backwards-compatibility in the C language and libraries written in C makes it possible to mix code that was written for different versions of C or that use different versions of the same library.