What could be the reasons for the appearance of hot pixels on devices?

Question

Iron

The essence of the problem: a huge amount of white pixels appeared, scattered all over the screen. It is visible only in the dark and on a black background, but there are really a lot of them.
Everything would not be so sad if they did not appear on absolutely all devices, regardless of the manufacturer.
The first victim was Ipad 3. Well, it happens that I successfully replaced it under warranty with a new one. After a couple of months on the new absolutely the same picture.
I got Xiaomi Hongmi Note - everything is the same.
Who understands the display device, tell me, what could be the problem? Nothing connects these three devices, except for recharging from one laptop.
I am attaching a photo, pixels are perfectly visible when approaching
Photo with pixels

Answer 1

Are you sure it's not dust? Usually burning pixels are bright enough.
The causes of occurrence are most often either marriage or mechanical impact.

Answer 2

maybe the devices remain turned off for a long time in the cold, and then you turn them on without waiting until they warm up to room temperature? from frequent sudden temperature changes, matrix defects can occur.