For any large code base to be maintainable, the programmers involved have to be disciplined and experienced, regardless of the language. For example, my own style of python coding has evolved significantly over the decade or so that I have been writing python code.
I just find that python leads to much higher maintainability than C++. The advantage that static typing in C++ brings is easily compensated for by just using descriptive names in python.
However, I dont really want to get into a debate on the relative merits of various languages. If you are happy with C++ -- more power to you
