Doesn't affect the device. The limited write lifetime of Flash is a natural consequence of how they work.
Data on Flash drives is safe because the bits are stored by electrons locked in a very well isolated layer. These electrons, if present, produce an electric field that can be picked up by a nearby transistor. Since they're locked up, reading out the transistor doesn't affect the electrons. During writes, however, to get the electrons through that layer Flash needs very high voltages. These high voltages cause some damage to the isolation layer, which accrues.
In comparison, DRAM doesn't have such an isolation layer. The electrons move quite easily. As a result, DRAM is faster and doesn't break down from writes, but the leaked electrons frequently need to be replaced. Turn off the power and they're all gone in milliseconds.