What rubbish! You do not need objects to make a library. Structs, typedefs, and functions do just fine. There are even techniques in C to define abstract data types if you want!

Take another look at https://developer.gnome.org/glib/stable/glib-Strings.html#g-... . That’s all C, baby, and could be replicated in a completely independent strings-only library built on the standard library if you wished. The reasons no such library exists are ecological, not technical.