"Teslanomics" says real-world data on Tesla EV batteries from users suggests they'll last "forever" or 23 years....whichever comes first, I guess. :-)
GZ can't link to this.....so here is the link. https://youtu.be/Gb_i4ihsJ1w
I'm confident that even 10 years from now the cost of a new battery will be much less than what it is today - and there will be the option of getting higher capacity still for less money than what today's battery costs.
If you compare the battery to a tank of petrol - the petrol can be gone in less than a day and you will need to buy more. Sure the petrol doesn't cost as much as EV batteries, but you have to keep replacing it over and over and over. I'm spending a couple of thousand dollars every year on petrol.
If I bought a 2nd hand Leaf for $15k and could make my 70km return trip commute on one battery charge every day for over 10 years then I would have saved more than the purchase price of the car in fuel costs. 70/135 = 52% so I guess I'm thinking I would be OK until the battery drops below 60% of the original battery capacity which should take quite a while. I think that the economics of running an EV for your daily commuter can look quite good for a lot of people, even more so for city commuters where the idling engine wastes a lot of petrol.