Every single C++ project of any significance I've worked on or seen in the wild has some awful dependency compilation script/process. It sucks. There are no good cross-platform solutions. Even if everybody is using CMake perfectly, you still have to glue all the pieces together.
But hey, modules are coming in the next couple years. Should really help with this.
Most projects with any user base provide ready binaries which able to get going pretty fast.
But what about the dependencies of those binaries/libraries? Manually playing that cat and mouse game just sucks.
I think you are exaggerating. Most projects with any user base provide ready binaries which able to get going pretty fast.
"it's so bad that big C++ projects like Firefox and Chromium basically write their own scripts that download and build dependencies, and simply commit the source code of the libraries they use directly into their own tree."
I would not call this 'bad' but resilient.
"Replicating is bad" is a non value adding rule of thumb, imo.
That said, yes, it's very hard to start incorporating third party libraries to C++ when compared to any other language.