The technical price for a larger sensor or larger pixels is lens size or lens speed (largest aperture). Remember that maximum lens aperture is a function of image size, so if the sensor (image) size increases, the lens must expand proportionately, the maximum aperture will be smaller (higher numerically), or both.
The Olympus (film) Epic is a lovely camera, but it is limited to a fixed 28 mm focal length f2.8 lens, albeit a very good one. Note that zoom lenses in P&S cameras tend to start at f4.0 or slower (bigger number), and have a largest aperture at maximum zoom of f10 or worse! They MUST use ISO 400 film to get hand-holdable shutter speeds. (Check out flash range at telephoto with these cameras for a shock.) So I would not use them as a comparison with the G series. And yes, I have several of the better (usually earlier) ones that served me well, but nothing like the G3.
In comparison, the G3/G5/G6 have that very nicely compact f2.0-3.0 4X zoom. That is amazing capability for low light and flash photography that is not available without huge cost, weight and volume in 35mm film or DSLR. I'd have preferred that the G-series and their competitors stayed with small 4-5 megapixel arrays and improved the focus speed, noise, chromatic aberration issues by product evolution. Obviously, the market doesn't agree with that suggestion, although I'm quite pleased with reports of improved performance in the G6 in all those directions.