Even with the “backlight” it’s far less harsh than an LCD or OLED panel because it’s not actually a back light, e-ink display have a “frontlight” that actually directs the light back at the display instead of from behind it facing outward towards the user
I use my e-reader’s dark mode when I am reading in the dark and the backlight is on. So, in the one instance where it is actually emitting light.
Even with the “backlight” it’s far less harsh than an LCD or OLED panel because it’s not actually a back light, e-ink display have a “frontlight” that actually directs the light back at the display instead of from behind it facing outward towards the user