The ptc heater has failed. When the ptc heater fails it also fries some portion of the dc to dc junction box. Total bill to repair "Drum Roll Please!" $6,977.14. Nissan will accept no responsibility for any of this.
You can find this type of anecdote for any brand and most models of car, most of them fossil fuel of course. And then you find the opposite anecdotes of people driving 300 000 miles or more with their cars and saying they are still in perfect condition. So it's best to just ignore anecdotes. More reliable sources indicate that these days cars can last 12 years and 200 000 or more miles and even 300 000 miles for electric cars (but probably not Nissan Leafs due to their poor battery design).
300,000 miles for an electric car? Yeah if you keep replacing the battery. But that was just my point a used car is not worth replacing the batteries! All lithium batteries age out to about 70% performance until they suddenly die. That die off is around 100,000 miles. Whereas most gas cars are still going at 200,000 miles. It will never make economic sense to invest in new batteries for used cars.
You can't cheat the phone company.