Ahem.... No, they don’t drive more because they drive a Leaf. They drive more because they need to for whatever reason. They then bought the Leaf under the assumption that it would save them money. Whether it actually does or not is not in evidence.
$7/gal gas vs $0.50/gal gas equivalent. The car might cost more up front, but the savings are significant.
Admittedly, EVs have a practical lifespan of about 6-8 years. While the rest of the car may be in good shape (really not that much to go wrong on an EV), when the $10,000 battery dies outright you’ll probably want a new car.