You're conflating energy and power. Maybe the truck doesn't burn energy 20x as fast going down the road, but if we compare the fuel efficiency of cars to semi

You're conflating energy and power. Maybe the truck doesn't burn energy 20x as fast going down the road, but if we compare the fuel efficiency of cars to semi trucks, it's apparent that trucks burn at least 5x as much fuel as passenger cars. But the truck does need to burn 20x the energy to go up hills so the system efficiency is going to reflect the weight difference. We can decompose the friction into two categories - air friction and mechanical friction. The mechanical friction should scale linearly with the weight, air friction is the larger term at freeway speeds so maybe trucks aren't that bad but they're not going to make an electric truck that can carry a profitable amount of cargo with the current technology. Scale the numbers accordingly, but there's a max weight of 80k lbs. Every ounce of battery cuts into the payload that pays for the truck. Battery technology just isn't there for heavy transportation - it'll get there and I hope it gets there soon but in the mean time, we should have a conversation about using fossil fuels better.