It is too easy for people to forget that C was not always the language of "libraries and embedded", and that writing large systems programs in C, of the sort that nobody would realistically consider writing that way in 2022, was a norm. Displacing C doesn't just mean rewriting existing C dependencies, but also changing the balance of decisions about which new programs to write in C. Go has had a tremendous amount of impact there. Without Go, Docker would almost certainly be a large ball of C code.