There are many reasons which lead to a cleaner codebase, some of them are: RAII, smart pointers, constant types, reusable containers, standard algorithms library, cleaner way to define interfaces, etc.

Overall our experience is that C++ code is smaller, simpler to write/read, and has a smaller chance of mistakes than equivalent logic written in C.

Of course many of this points are relevant only for relatively modern C++ (c++11/c++14 or newer), before that the cost/benefit ratio was much less clear.