I'm trying to picture the car that is worth only 5 * monthly-lease-price when it is 3 years old, and the only way that makes sense is if the car is expected to require very significant maintenance costs beginning after year 3.

Monthly leases are usually a small percent of a car's new value (e.g., 3% over 36 months would exceed the cost of buying it new even ignoring lease downpayments, fees, etc).

Over 36 months the car should depreciate and the lease costs as percent of current value will naturally rise, but this scenario presumes monthly lease price reaches 20% of the car's value which is absurd.