C and C++ will eventually die in the same way that COBOL has died. That is, they'll never go away, but there will be fewer and fewer people able and willing to use them.
People have been predicting the death of C and C++ for decades now and those two languages are as strong today as they ever were. BASIC and Pascal were supposed to kill them in the 80s on microcomputers. Java was supposed to kill them in the 90s, now people think Rust will do it, but history shows that to be pretty unlikely. C and C++ have an immense amount of inertia that is unlikely to be stopped any time soon.
> You're making the flawed assumption that all consumer
> devices have a brand new stack of software written for
> them, which is absolutely false.
> People have been predicting the death of C and C++ for
> decades now
Also, I'm not sure why you're talking about C and C++ as though they're the same language. C's biggest long-term strength is ubiquitous platform support, and those platforms do not support C++. I see C as being unassailable in this space. But C++ is doing its damnedest to cling to the low-level application niche, and while it's going to continue to dominate there for the foreseeable future Rust is going to give it a run for its money.
In the meantime, Rust doesn't need to kill C++ to be successful. Rust's best niche--that is, safety-hardened low-level applications--is more than lucrative enough to sustain it, especially with a major player like Mozilla proving its utility. And thanks to this same safety, Rust is seeing use in niches that C++ has never gained traction in, such as being a language for writing extensions for dynamic language runtimes (traditionally a task for C).
Search indeed.com for
C++ : 4287 jobs.
golang : 71 jobs
Java : 6817 jobs
Rust : 7 jobs
Anyway, if you're going to take a purely mercantile approach to evaluating programming languages, you should consider the salaries these employers are offering rather than the number of job listings. Consider supply as well as demand.