It also doesn’t mean that at 8 years and a month the battery collapses into a state of disrepair and needs complete replacement.
I hope not, although I didn’t say that a battery will fail a month after the warranty runs out however they will degrade and you will find manufacturers small print states an acceptable battery capacity of at least 70% of the original specification after seven or eight years is acceptable.
It is possible to replace a cell or a pack but, its not common practice yet and cars the fact manufacturers are building batteries into underfloor of vehicles,it can be labour intensive and may not be practical due to how cars are being manufactured.
Whether you have an EV playing some tune or a roaring V8, some muppet of a pedestrian will always step out in front of you!