If you want speed, don't get a Hybrid, get a TT bike.

Hybrids are compromises, you are normally trying to get a mix of speed, comfort (so you arrive fresh, not as the comfort bike) and carrying ability.

After the rider, as Seve noted it's aerodynamics, any people aren't that aero, tires make a big difference with rolling resistance, wheels with rotational weight more so than the frame weight, and components only make a big difference if they don't work; for % no idea as too many variables,