Bigger issue seems to be people overestimate how much they spend on fuel. You buy the car once, but you refuel it hundreds of times over its lifetime, giving the impression that fuel is a big expense.
For example, if you assume $0.073/mile, for 100,000 miles, that is $7300. If going electric cuts that in half, you save only $3650, which is only ~10% of the cost of the vehicle.
Looking at total cost of ownership (car + maintenance + fuel) makes much more sense than just fuel.
It's even worse than that, because eventually the battery pack will have to be replaced.
While Tesla may cover that under some warranties, people who bought something like a Nissan Leaf are SOL. Their cars start losing range much quicker than a Tesla, because of the need to charge almost daily due to lower range.
Google shows the replacement cost for a Nissan Leaf battery at $5,500. Going by your calculations for 100k miles (which is Nissan Leaf's warranty range for the battery), the electricity cost will have to be $1,800 for it to make sense to buy. That's going to be nearly impossible to achieve.
The math starts to become a bit better at $4/gallon, though.
Does that replacement cost for the Leaf battery include the core credit for returning the old battery? Those batteries still have value, and if they can be re-manufactured or re-purposed as stationary storage batteries, that could reduce the cost significantly.
Depends on how much the old battery is worth. It's like replacing your transmission in an ICE. When you replace your transmission, you get a rebuilt one for like $1k. The actual price for a transmission is like $2, but if you send them the broken one from your car to rebuild for the next car, you get a Core credit.
For example, if you assume $0.073/mile, for 100,000 miles, that is $7300. If going electric cuts that in half, you save only $3650, which is only ~10% of the cost of the vehicle.
Looking at total cost of ownership (car + maintenance + fuel) makes much more sense than just fuel.