May be 20-30 years down the line, if it stays may be enough OS and libraries are built in native Rust without C then it might displace it, but at the moment Rust depends on C.
Right now Go is miles ahead of Rust when it comes to libraries and ecosystem. So it needs to catch up and once it overcomes Go popularity it might be nearer to C++. C is a different beast and will continue to be there it's the lingua franca of hardware programming and abstraction, unless something simpler comes and takes over which will also be 2-3 decades.
I'm not sure that's true. A couple of years ago sure, but Rust is growing very fast.
I also think there's no reason to think C will stay around forever. The C ABI will be the lingua franca, but that doesn't mean you need to actually use C.
The only reason it has persisted for so long is lack of alternatives, but now we have at least Zig and Rust. Obviously there's a ton of momentum so it will still take a while to be replaced but I wouldn't be surprised if e.g. musl switches to Zig or Rust fairly soon.
