Only old C++, new C++ creeps up the y axis.

Interesting perspective. It surprises you in exactly how, but not very in that it will. (Horrify you. But it also delights sometimes. We need more dimensions?)

To put it differently, the new C++ is delightfully horrific at times.

C++ occupies a region of the space rather than a singular point, since old C++ is part of new C++.

I’d say C++ fills the space. It can be as dumb or as clever as you want it. It’s horrifying in a third dimension.