You can recover quite a bit more data from highlights and shadows in RAW, along with much better control over color balance in post processing. Additionally, it removes issues of in camera settings such as sharpening and noise reduction, which can have artifacting or destruction of detail. It isn't that you gain pixels with RAW, but rather detail in color and contrast.
If you have no intent to post process your images, you'll see no reason to use RAW. But the reality is most images require at least a bit of post processing to have the desired look. I have a great deal of images from when I first started shooting digital that I wish I had shot in RAW instead of JPEG, as my increased understanding of post processing would allow me to do much more with those images now than I could then. Earlier this year I somehow got my EOS M to shoot JPEG only and, needless to say, I regret it as several shots in dark bars and such are unrecoverable in JPEG that I could easily have pushed values on in RAW.
A great example of a shot, well a set of shots, that RAW let me save from years ago is this
panorama. I had used aperture priority without thinking about the difference in exposure required for the fields between the left side and the right side (about 2 stops difference) so the initial stitching from JPEG (how I was building panoramas then) was much, much darker on the left than the right. Going back years later, I corrected the exposure difference in RAW, then set about merging the images again to create the more balanced one I've linked. If I had not had RAW files, the artifacting from pushing my shadows would have been obvious and effectively unusable, where as with this I've made 12x36 inch prints now with little issue. Keep in mind, this was shot with my old XTi (10mp) and the very crap kit lens.