Eh, I'd call them culturally close. I always read it as "the most common systems programming languages", since that's how the phrasing is usually used.

Even that can be disputed. They typically have quite different domains of applications. Gamedev is seldom done in C; operating systems are seldom done in C++. Their different level of abstraction ends up having them applied to different things.

Going to be honest, whenever I see or hear someone put them in the same category, it usually colors my impression of said person as essentially never really learning C++.

I would assume a lot of recruiter-types or folks just getting their feet wet into programming would assume C++ is just a newer or more powerful "Edition" / "Version" of C.