> All languages back then, all of them, were "high-level" languages, including C.

The only interpretation where this assertion rings remotely true is if you follow a definition of "high level language" which boils down to "it's not assembly", which has not been the case for around half a century.

It makes absolutely no sense to claim that languages such as COBOl and C are even close at the same level of abstraction, just because C is compiled, has loops, and has a standard library.