This post is just a simple thought-
C is sometimes referred to as a portable assembly language. There are several articles argueing that this is not true, and this rings true for me and my experiences with C, where it does not really match the hardware architecture (at least, not anymore), where it does not give enough control, where it does not really map down to assembly in the way one might expect.
I think there is a small modification that makes this statement true- C is not portable assembly, C is like portable assembly.
What I mean by this is that on modern processors, the Instruction Set Architecture (ISA) is not executed directly. It is the interface between software in the hardware, and gets interpreted into an even finer microcode language that is actually executed. The ISA is the specification, the interface, the constant that leaves both sides able to talk and change without constant deep knowledge of the other side.
Compare this to C- how many languages have C as their main, if not only, FFI? How many languages compile down to C, or are implemented in C, or run on operating systems written in C? You can implement system calls yourself with a little assembly, you can compile to assembly and use an assembler, you can use Clang or equivalent. However, in general C seems like it is the lingua franca of computing. It is the baseline, the language level, a step up from machine code, above assembly, but below almost all other languages.
In this way C serves a similar purpose to assembly language- just as assembly is an abstraction that serves as a language layer underneath the world of software and above the world of hardware, C is below the world of high level software, matching it up to hardware and operating system specifics and providing some buffering from the details below.
This is a bit half-baked, but I think the idea holds up fairly well. C does not really match hardware, its closer to being the foundation of software.