Sure, but there are limits. One needs a certain amount of forward speed to maintain balance easily, and there's a maximum speed that can be reasonably pedaled. If the hill is steep enough then in my experience reducing the gearing enough to make pedaling not too strenuous runs into the other two limits. If an e-bike can have a low battery topped off before the hill starts, then pedal-assist (at least) would take care of the need to lower the gear while going up it.