You can think of simplicity in various ways - some subset of which are valid. For example, you could say that using std::unique_ptr is simpler than manual memory management, because it automates much of the process, making it less likely that a developer will make a mistake. Or you could say that the 1000s of lines of C++ std code that you will pull in represents an increase of complexity, because the mechanics are hidden under layers of abstraction.

I'm open to both views, and most importantly to trade-off one against the other according to other constraints and context. For me, using C++ allows me to do that, because it's (mostly) a superset of C. Acknowledging, of course, that this brings a trade-off of its own, because decisions must continually made (and enforced) about what std/external libraries to use and when.