[Gibbon1]

You can look at actual numbers. Instead of a Model 3. Lets compare a Chevy Bolt with a Prius.

Chevy Bolt is about 3500lbs Prius is about 3000lbs.

Chevy Bolts battery weighs 440 kg or about 968lbs.

Reduce the battery weight by 1/2 and save 484 lbs. So the weight drops to 3016.

So point stands if the battery power density improves 2X then the weight penalty disappears.