Your friend is correct—Teslas do literally outweigh the competition. The Tesla Model X weighs 5,594 pounds and the compact Tesla model Y weighs 4,386 pounds. This is their curb weight, which is simply the weight of the vehicle with no passengers or cargo in it.
By way of comparison, a typical compact SUV like the Model Y weighs between 3,000 to 3,500 pounds, while a midsize one like the Model X is around 4,000 to 4,500 pounds. What accounts for the extra tonnage?
That would be the battery and the electric motor (or motors), both of which weigh quite a bit. Add on the heavier frame that’s needed to support that additional weight, and you can see why Teslas tip the scales a tad higher than their non-electric counterparts.