It is a combination of technology moving fast (aka nobody wants an old ev that does not have the latest advances in capacity and speed of charging) and also the real fear of battery replacement costs.

For the second one insurance companies could help alleviate the uncertainty, but I don’t see major vendors offering packages.

People don’t have 20k in a single shot to fix a battery failure. (Maybe cumulatively for a gas car one has to pay more, but it will be in small installments)