C++ has survived more than one wave of technology churn. It has lost market share time and time again, but hasn’t /bowed out/. I feel SQL, Unix and shell-scripting are similar survivors.
C++ is by far the most difficult languages to use and learn. (You can learn it in 6 months but likely very superficial.) Yet many companies still pick it instead of java, python, ruby — sign of strength.
C is low-level. C++ usage can be equally low-level, but c++ is more complicated than C.