How did Tesla test product life? The cells are not EV cells. The use-case is not in a car. The product delivers a maximum of 5kW charge and discharge power which is pretty light work for a 13.5kWh battery (my hybrid can generate 80kW from a 6.2kWh battery). I doubt the product life is as short as you predict.I assume all manufacturers test and know the life of products then issue a warranty for something like 10-25% less of projected life. It would be very generous of them to allow a product life of 50%. more than warranty. I gather their 10 year warranty is for a remaining 70% efficiency but my payback allowance was for 100% efficiency over 20 years. I suppose dead is the wrong word for battery performance but if the battery falls below 50% then payback period doubles so the economic viability is dead.
Also, you appear to be saying that most fossil fuelled cars will be dead 40-45 months after they roll out of the factory - that’s 10-25% beyond their warranty period. My washing machine is still running after 20 years - that’s 1000% of the warranty period. Have I missed something?