Regarding the CMake documentation, though, I have been relying on it forever (that's pretty much how I learned CMake), and I personally find it pretty good. That is where I believe there may be some kind of cultural change: I am fine reading the manual (`$ man <command>`) and RFCs and documentation like the CMake one. It feels like "the modern way" is to find an example that does what you need and mimic it (hence the success of stuff like Copilot).
I just feel like my way is more powerful: I can both leverage official documentation (and RFCs, etc) and examples, and I can actually use them together (e.g. read the example, see new stuff there, and go read the official docs about those new things). IMHO, only being able to rely on examples that do almost exactly what one needs is a bit of a loss; people should learn to read actual manuals.