Because a regular car wouldn’t come close to the reload costs
tbats why they should stand behind there products and not make it unaffordable for the average
You're right that the price for battery replacement is a problem for EVs in general, it's not necessarily only a Tesla problem. Part of the problem is perception. People think, "A $20K repair on a car only worth $30-40K isn't worth it." However, I think an EV with a new battery is actually a much better value proposition than a gas car with a new engine, for instance.
It was made worse for you because normally, the low miles means less wear, but batteries wear out just sitting and doing nothing, so the calendar time was more pertinent.
All that said, I think the third-party repair options are the saving grace here. They can pretty easily put in a newer, used battery for less than Tesla charges, and that's a reasonable route to go for an 8yo car.
That's the stance I'm taking with my RAV4EV. I just ran out the 8 year extended warranty I bought. I tried hard to buy another from Toyota, but it was no-go. But I happen to have a local shop that does repair work on them, and I've talked to some other folks who have expressed that they would probably be able to come up with a battery solution if that ever became a need. Meanwhile, I take care of it the best I know how.
Edit: It can be a problem for gasoline cars, too. Owning a 8-10yo high end BMW can also open one to some gnarly repair bills, if you're unlucky, and you only go to the dealer for repairs.