> I compile a lot of C++ code from a lot of places, and the only time I run into code that somehow simply doesn't work on newer versions of C++

I'm impressed that you even get as far as finding out whether that much C++ from disparate sources works on a newer version of C++. The myriad, often highly customized and correspondingly poorly documented build systems invented for each project, the maze of dependencies, the weird and conflicting source tree layouts and preprocessor tricks that many projects use... it's usually a pain in the neck to get a new library to even attempt to build, let alone integrate it successfully.

Don't get me wrong, we use C++ and ship a product using it, and I occasionally have to integrate new libraries, but it's very much not something I look forward to.