Well, it is impossible. It just doesn't work mathematically. All things being equal, a 10% boost in power does not take you from 1600x900 to 1920x1080 because going from 900p to 1080p is an increase of 44%.
"Power" is not a single measurement that has a linear relation to a game's resolution. What you're saying kinda-sorta applies to fill rate, but we don't know if that was Destiny's main bottleneck.