EV's are heavier because they have large, very heavy batteries in them. If an ICE car was larger and heavier, that was by choice not required by design.
For example, the original Tesla Roadster versus the Lotus Eliese--same exact car except for the drive train has the Lotus weighing in at 1600 lbs. while the Tesla weighs 2800 lbs. (in round numbers). That's a 1200 lbs. increase due entirely to the battery.
It does not matter why. ICEs in many cases are heavier. Have you checked their mileage? Many ICEs were specifically designed to be huge to make trips with heavy loads more comfortable.