There are tons of places where Rust and Zig don't have a solution, or are not part of an industry standard that builds on top of C and C++, like GPGPU, Khronos standards, console SDKs, ...
Additionally while they keep being built on top of C++ compiler infrastructure, C++ isn't going away.
Sure now that is the case. But which do you think will happen first - C++ will get working modules or people just give up on C++? Definitely not clear cut!
Additionally while they keep being built on top of C++ compiler infrastructure, C++ isn't going away.