I'm pretty sure C++ is used for exactly the game thing Go is used for. And C++ is used for a lot of other things as well. In fact, you will probably have trouble finding a problem that wasn't solved by C++ by somebody. Scientific computing, server process, CRUD applications, embedded applications, AI, graphics, programming languages, libraries, etc.
C++ has a lot more features and therefore it's actually able to be used for a lot more things. People that don't need a language that can be used for every possible computing problem think that maybe C++ is a tad too complicated. Those people certainly have a point.
I don't think it's the feature-set that makes C++ viable for more situations than Go. In my opinion that's only because Go uses managed memory. That takes part of the runtime behavior of the code out of the hands of the programmer. This counts out Go for situations where you need precise control over runtime behaviour.
That said; C++ is a ridiculously complicated language. I don't get why people think that Rust is difficult.
C++ has a lot more features and therefore it's actually able to be used for a lot more things. People that don't need a language that can be used for every possible computing problem think that maybe C++ is a tad too complicated. Those people certainly have a point.