Though drive-by-wire throttles absolutely do modify and potentially hold back your throttle input for reasons of both economy, comfort and enforced driveline sympathy, there is also an inherent response difference between petrol and electric engines and also slop in the driveline system. That difference varies on the engine and transmission type.

Unfortunately I cannot find an easy good reference on what exactly that difference is quantifiably. Also many of the Electric cars right now are higher end even sporty vehicles, and more likely to have a throttle mapping that is more direct.