It's not actually the transistors that break down in flash memory. Flash memory works by storing charges in what is effectively a grid of capacitors, and in order for the data to remain stored, the insulating oxide layers in the cells need to be preserved. Every time a cell gets written, a charge is forced through the insulation with high voltage, and this degrades the insulation. A single flash cell might only have a few 1000 writes before this insulation goes bad and it no longer holds data. Modern SSDs have wear levelling techniques to make the drive as a whole last longer.

Transistors on the other hand don't have any inherent degradation that I'm aware of other than external factors like corrosion. The first thing that's likely to die on a GPU is the electrolytic capacitors in the power filtering electronics, which have fluid in them that dries out over many years.

I doubt the transistor on a GPU wafer break after 100k cycles, as they run at gigahertz frequencies, some cycle billions of times a second.