Wellp, this is about unpopular opinions, so in that sense I guess it fits, if everyone’s getting their undies all in a twist.
Thing is, I’ve seen phone “flashlights” in 3 different varieties: screen goes full white, lit by the backlight; camera-flash LED doing double-duty as a “flashlight”, and a dedicated teeny 5mm LED or so being used as an actual flashlight. They’re all kinda silly, just as pliers on a SAK. They might be better’n nothing, but not by much.
I’ve got key doodads that slip onto the key itself and have a built-in coin-cell and LED. I’ve also got dedicated blanks to serve that function (available at your friendly neighborhood locksmith). Squeeze to light it up, and it lights up the keyhole perfectly right where the key’s going. Limited lifespan of the cell, usually nonreplaceable, so not quite suited for general-purpose lighting.
In any case, when something rolls under the couch, or falls under a car-seat, or drops down sewer-grates, using a cellphone for lighting would be either useless or retarded (unless you don’t mind the phone falling down the sewer, in a toilet, between cabinet and wall, etc.).
So even an AAA light would be better. Some twisties being barely bigger’n the cell itself, they could be put to good use by quite many people.
But hey, we have our choice of AAA/10440, AA/14500, 16340, 18650, whatever. You wanna carry a Q8 strapped to your belt, hey, go crazy.
So… can’t we all just get alooooong? [snark]