The fact that other car makers aren't competing on warranty length seems to me to prove my point, but you seem to think it doesn't? What I mean is: if battery degradation for cars isn't that bad after 8 years, then why are other brands not offering significantly longer warranties to compete with the Tesla one? Not sure about the competition argument anyway, since Tesla didn't have any competition initially and arguably still doesn't have real competition (depending on what features of the car you value most).
Edit: Does my MacBook Pro die after 1 year when it's applecare warranty is over? --> Pretty close yes IMO. My personal experience is that my laptop and phone battery capacities degrade very fast after 1 year and need to be replace after about 2 years, 3 years if you really really push it and are OK with constantly charging.
