Except in the darkest environments or most extreme magnifications/resolutions (e.g. astronomy) or fastest speeds you're already shot noise limited. Getting a Quantum Efficiency of 100% and 0 read noise is much more difficult than combining many images (like HDR and discussed in the article) and improving image stabilization.

Think about how much light you throw away going through the Bayer Filter (RGBG) vs stacking photo-sensors... that's already >60%.