I've been using an eInk screen for over 12 years - it is refreshed multiple times per day.

It is as crisp and clear as the day I got it.

Admittedly, I'm not trying to run video on it constantly and it doesn't get hot. But eInk seems remarkably durable.

That's probably, what, 200,000 refreshes?

From what I gather, at book-reading speeds, newer e-ink displays may never wear out in a human lifetime.

But at usable computer display speeds I rather suspect many of these panels have a lifetime one might measure in months.

from 6.7 to 42 would be my guess.

But being serious, I personally have not seen a degraded e-ink display.

I've seen a couple minor, older-hardware cases when they've been powered off with something on the screen for years, but that's about it. in theory they can also "burn in" by not clearing the display occasionally (afaict it has something to do with accumulating charge) but most or all of those should clear eventually after cycling a bunch (afaict, though it can definitely persist to a minor degree for dozens of full refresh cycles). extreme ghosting, basically.

they seem pretty durable to me.

Even in a lot of direct sunlight or leaving it out in the heat?

No clue, I've only seen either fully working or physically broken ones. Oldest one I have still has mini-usb and no degradation can be seen. Though I only rescued it this year, it seems like it was used pretty roughly.