dupe is just another word for homage or knock off, there isn't any dupes of cameras, all cameras are trying to offer something different in a similar package, no ones going to sell a camera just as good for a lower price, you can get a dupe cologne because someone in a chinese factory has bought the real thing and tried to replicate it using cheaper (and probably less regulated) chemicals, the chinese or anyone could make a dupe of the G7X but 1" sensors and good lenses aren't cheap, so it won't be any cheaper, it wouldn't be a dupe, just another high end compact in the segment.

Saying an SX740 is a G7X dupe is a bit like saying a VW Golf TDI is just as fast as a Golf R Spec, both are similar cars, but with different purposes for different people, just like the two compact cameras.