this is taking about the efficiency of creating the increased pressure. turbos are powered from exhaust gases, so are kinda "free" power so to speak. while superchargers are using the engine to create the power but at the same time, drawing some of it for themselves. so it doesn't matter how the car is driven, the engine is less efficient or slightly restricted by the supercharger because of the increase inertial forces required to turn the engine.
as said before this leads to a less responsive engine and less gains from peak revs.
if you're driving hard, lag should be no issue and if it is, your revs are far too low
also, if you're running 1bar on a supercharger, it's still going to take some revs to produce that much pressure. down low is better but it's not perfect.