What happens when a block is erased 100,001 times?
Even with a perfect wear-leveling strategy, your flash device will have a limited lifespan. Do not focus on device behavior towards the end of its life, and for simplicity assume that once one block has been erased 100,001 times, the behavior of the entire device is undefined. You should adopt a wear leveling strategy that prolongs the life of the device for as long as possible.