a LED has nonzero cost. The case having a hole for it also has a cost, as does engineering the hole not to be a weak point. It may not be hard or expensive, but nonzero nonetheless.
The software to control a reliable AOD LED light is trivial.
Some phones like OnePlus do temporary lighting. Persistent lighting without burn in is doable and I wish someone would take it up. Aodnotify is glitchy.
> figured out that a bright, persistent,
> multi-color LED/OLED notification is
> a desirable zero-hardware-cost feature.
a LED has nonzero cost. The case having a hole for it also has a cost, as does engineering the hole not to be a weak point. It may not be hard or expensive, but nonzero nonetheless.