C/C++ will be replaced incrementally and it’s already happening. Cloudflare recently replaced nginx with their own alternative written in Rust for example.
That's nice, but a couple of Rust rewrites are not proof of a general trend.
I've been working with C for over 30 years, both professionally and a hobbyist. I have experimented with Rust but not done anything professionally with it. My gut feel is Rust is too syntactically and conceptually complex to be a practical C replacement. C++ is also has language complexity issues, however it can be adopted piecemeal and applied to most existing C code.
> My gut feel is Rust is too syntactically and conceptually complex to be a practical C replacement.
That would depend on what you use C for. But I sure can imagine people complain that Rust gets in the way of their prototyping while their C code is filled with UB and friends.