At lower revs the turbo is more likely to boost the engine if you demand power, of course depending on the dimensions of the turbo, but it doesn't make sense to put a performance turbo that works in the upper rpm range, in a regular car.

In any case, an electrically assisted turbo is not a replacement for this. This is a way to have high compression at low loads, such as highway crusing, and ability to lower compression when boost is needed for performance.