What many people underestimate is all the comfort stuff we have and use in modern vehicles. Most of the utilizes some sort of electric drive. Any electric drive requires power: * Power sliding windows * Power seats * Electric trunk * Power sliding roof * Electric mirrors

Also other stuff: * heated back window * heated front window * heated seats * heated steering wheel

Also the lights, even when they are LED they still draw a lot of power: * front lights, * back lights. * surrounding lights * comfort lights

That is just of few devices. Just look into all the comfort in a modern (luxury) vehicle.