The exact wear mechanism doesn't really matter (you must be referring to "hot carrier injection") --- the point is that to record data, electrons are being forced through a material which gradually wears it out.

That was also my point. I was just pointing out that the idea that electrons shoot through the insulation to end up in the floating gate was not true.

Thermal wear? I thought it was mostly based on write cycles. How can that be 'thermal'?

The write cycles are realised by moving electrons through a material. This creates heat, which leads to gradual degradation of the material.

Does the individual gate get that much hotter than the rest of the device?

If I keep my SSD 40 degrees cooler with a freezer, will it last an indefinite number of write cycles?

I just looked this up, and it turns out I was completely wrong about how the wear is caused. Apparently it’s due to a build-up of electrons remaining in the floating gate over time, and not general thermal wear. It turns out that heating can even reverse this wear. Explained in this link: https://arstechnica.com/science/2012/11/nand-flash-gets-bake...