Compiler optimizations don't really help if your code is I/O or input-bound, which accounts for most of the code written today - so users rarely see the benefits. Occasionally you get a situation where one particular code path is CPU-bound and is hit often enough that optimizing it matters, but in that case it's usually still easier to use C++ for that particular bit, and some other high-level language for the rest.
Granted, with all the changes already in C++14, and more good stuff coming in C++17, C++ itself gets more high-level every year. Right now I'd say the problem is really more with the tooling than with the language... debugging C# or Java is still a much more comfortable experience than debugging C++. But it doesn't have to be that way.