If you look at projects in more popular languages like JS, Rust, Python. There is plenty of new blood in the contributors list. I won't speculate as to why, but it looks like the new generation doesn't like c and c++.
I think this is also backed up by the Linux kernel and thunderbird projects. Both are old c/c++ codebases and both have stated they are adopting rust in hopes of drawing interest (and contributors) from the rust community.