system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do lightbulbs go out, but not the lights that illuminate screens on TVs and phones?

Is it even possible for them to go out?
gpt
it is, DLP tvs for example used a honest bulb (though very bright and powerful), and it had a life of a few years.

LCD screens use edge lighting, most are LEDs these days (all cell phones), but they used to use compact florescent lights (rarely still do).  both have absurdly long lifespans, longer than the devices they are in.  but its possible for the backlight to fail.

the newest phones (and some TVs) are OLED, which means the screen itself are itsy bitsy LEDs that generate the light themselves.  again, super long life.