Electric pickups differ from combustion-powered compact pickups chiefly in how they store energy, deliver power, and replenish that energy. Their dimensions and carrying ability are separate questions. Electric describes propulsion, while compact describes size; a pickup can have both attributes, and an electric model is not automatically larger or more capable.
To make the comparison useful, identify two actual trucks. Compare the electric powertrain with the compact candidate's gasoline or hybrid system, then examine cab and bed space, rated loads, parking access, charging or fueling, and maintenance. That separates differences caused by the power source from differences caused by a particular vehicle's design.