VW Grammar help req from Beginner

Hello,
I just started reading a book which claims to explain parsing
techniques in a non-mathematical manner: "Parsing Techniques: a
practical guide." So far, it has done an ok job of explaining
languages and grammars, and the different levels of grammars. But when
it started explaining how CF grammars can be used to emulate CS
grammars, I got lost. I get the general idea, but what is the *point*?
Isn't having to generate usable rules from the hyperrules just as
inefficient, if not more, as having a long list of alternatives in a
one-level CF grammar? Any help in understanding why VM grammars are
actually useful would be much appreciated by this nonmathematical
type; if you could point me to working code (any language) using VM
grammars in action, I'd be much obliged.

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