This is based off general programming knowledge, as I have never used C++, but I think it is referring to a highly-modulated programming style that uses many general functions.
I.e., instead of writing a few quick lines of code to perform bisection search in the middle of logic flow, you create a general bisection search function and implement that.
This leads to high productivity "a statement per function", and makes code cleaner and easier to update, but can substantially increase overhead costs.
No, C++ is particularly well suited to that since it's possible to implement those with zero (and in practice less than zero) overhead. The problem is overridable functions; i.e. not generic implementations that work on various structures by compiler specialization, but methods on classes whose implementation varies at runtime by dynamic dispatch. E.g. a getLayoutWidth method with a different implementation for blocks and inline runs, and where it's possible to call the implementation without knowing at compile time which it is.
I.e., instead of writing a few quick lines of code to perform bisection search in the middle of logic flow, you create a general bisection search function and implement that.
This leads to high productivity "a statement per function", and makes code cleaner and easier to update, but can substantially increase overhead costs.