Initially coming mostly from the Java ecosystem with its mature (not perfect) build and dependency story, it took me days to understand that none of that exists in C++.

All of it seems to be based on copying dependencies around or installing them on a system level. Plus mostly template/text driven make files.

I'm still not sure if this is really how C++ is developed.

Four years ago, when I last looked, I wasn't able to find a good resource for people with my background to learn C++ the ecosystem (not the language).

That turned me to Rust. All of this text to give strong support for your first paragraph.