“C gave us similar advantages over writing in assembler.”
This is a profound misunderstanding of both C and assembler: C gave us portability, not reusability; writing shared object libraries with reusable code in assembler has been the bread and butter of programmers for decades, and it takes no longer to do in assembler than it does in C. A stereotypical example of this is the Commodore Amiga, where most of the shared libraries are written in assembler.
This is a profound misunderstanding of both C and assembler: C gave us portability, not reusability; writing shared object libraries with reusable code in assembler has been the bread and butter of programmers for decades, and it takes no longer to do in assembler than it does in C. A stereotypical example of this is the Commodore Amiga, where most of the shared libraries are written in assembler.