Notice that none of the lists write Java/Javascript or Go/Python because that would be silly, so why do they write C/C++?

Beyond that, take the ARM job. You'd have us believe that description says C/C++ meaning either C or C++. But it's an LLVM developer job. It says C/C++ because the person typing it up didn't think there's much difference.

Maybe ARM is open to hiring people who don't actually know any C++ for this position, there's no salary indication and it's not highlighted as a senior role, so perhaps they're hiring fresh graduates whose C++ would be terrible anyway, a few weeks of Kate's Pluralsight courses and reviewing other people's contributions might get good non-C++ candidates up to speed. But I wouldn't bet on it, applying if you aren't a C++ programmer is likely a waste of your time.

For the AMD one I can actually believe AMD would take a great C developer. They need Linux kernel support just as much as Windows, and unless AMD is going to start writing in Rust that'll be C code. If you send Linus code that thinks it's basically all the same he's going to have a meltdown and make your life miserable.

But for Apple we're back to I just don't believe C candidates will get this job. That's C++ software again, they just aren't outright admitting it isn't a C job, but once it's apparent you are a C programmer you don't meet their actual needs. Their mistake, not yours, but it's your time and effort.