It primarily depends on the size of the project. Past a certain size, I am definitely more productive in C++ than in Python. Though the compile-time checking of Cython might balance things out and make scaling a Python project easier.

std::visit is broken, sure. std::vector<bool> is a mistake, too. You don't have to use it. Select a subset of the language which gives you what you need. That's part of what's great about having so much in the language.