If we're going by best software written, I suspect that means C is the better language than C++ by a wide margin. It would be interesting as to whether Visual Basic would be superior on that axis as well.

C++ is the better language--except that we always have to expose a C FFI because nobody seems to have enough critical mass to stabilize the library ABI. C++ is the better language--except that Apple wrote another language because they don't believe that and that Mozilla wrote Rust because C++ wasn't good enough. C++ is the better language--as long as you have a new codebase that only uses the latest features and Satan help you if you have stuff from pre-2005 because God won't be enough. C++ is the better language--as long as compile time isn't an issue.

I can go on if you wish...

I don't think C++ developers are stupid and those choosing to start new projects in it generally have really good reasons for doing so. I also think that many older projects are in C or C++ via path dependence because C++ was the superior choice when the project started and now they have far too much code to switch.

I also believe this will be why Rust eventually becomes a very important language--Rust allows you to modernize that old codebase in a piecemeal fashion.