The complexity of C++ lives primarily in the fact that it is almost entirely backwards compatible all the way back to the late 1980s, and mostly compatible all the way back to K&R C.

Modern C++, when you stick to the new idioms (RAII, range loops, auto lambdas etc) is almost as compact and succinct as Python with type annotations. One of the biggest differences is readability is that the standard library is not "batteries included" so people roll a lot of stuff themselves.