If C++ is "(nearly) a superset of C" why is the C++ standard twice the size of C standard? Of course if we take that 0.505.. ≈ 1, then it is indeed a (nearly) superset.
That's nearly as in "most of C's features are supported by C++", not "most of C++'s features are C features".
It is only nearly a superset because it contains all the features of C except for a few like implicit pointer casts.