That we have a hard time thinking of lower level languages we'd use instead of C isn't because C is low level. It's because C is so damn successful as an abstraction over the underlying machine and making that high level, it's made most low level languages irrelevant. C is that good at what it does.
It seems obvious once I read it, but the point that gets made very well in this article is that C isn’t really a low level language. It’s just that C is so effective at what it does that there isn’t much reason to think of using a lower level language anymore, and so our perception of what a low level language is has changed.