Well, the comparison has to do with accelerating rapidly up to the same given speed, all else equal after that point. Also, mostly open throttle body an engine with drive-by-wire doesn't necessarily mean pedal floored (which will tend to "tell" the computer to drop the gear ratio for greater power). Also, another point of note with respect ot hybrids is that they have downsized engines to begin with to reduce partial throttle loss, so they will hit minimul throttle loss at a much lower acceleration rate than on a non-hybrid with an oversized engine.