I bought a used 2016 Leaf with the idea that I could use it for the next 5 years or so and then upgrade to a car with larger capacity (my car is only 30 KWh). Out of curiosity, I asked the sales person how much a new battery would cost in case I had problems: ~$7K. At that price (and assuming it's installed price... I forgot to ask), I might actually be tempted to do do a battery swap after the 5 years if the car is otherwise OK. However, it seriously doesn't look like I'll need it. After a year of use, the battery capacity doesn't seem to have moved at all. In the summer on the slow roads around here I even get about 230 km (~140 miles) range on that tiny battery, which is quite a bit more than I was expecting.

So with all that said, I wonder if they are on to a good idea. There is so little maintenance on these EVs that the occasional battery swap might be fine, cost-wise. You could even sell it upfront in installments -- new battery after x years.