C++ is not simple.
But presenting C# (or Java) as "simple" is equally hypocritical. The JVM or the CLR and their associated frameworks are monster of complexity, engineering and legacy that require close to an entire lifetime to be mastered entirely.
C# (or Java) are "accessible", meaning a newbie devlopper can produce something halfway baked in these languages relatively quickly.
And this is something you can not say about C++.
But they are not in any way "simple".