Explain Like I'm Five

Their absence encourages you to check your phone more often, which means you'll unlock it and look at some content more often, which means as revenue for someone.

Higher end Smartphones have anyway always on displays. And the led needs screenspace - which should be maximized. That's why the notch on phones etc. was introduced.

I also love notification LEDs.

I'm pretty sure the main reason for them disappearing is the displays extending all the way to to edge. There isn't any room left where to place it.

Also, on phones with always-on display, you can use the display to show notifications, the led is redundant.

But still, I find them really useful and am sad to see them being phased out.

Sony Xperia user here, I recommend your Next phone should be a Sony. Not only does it still have notification LEDs, it also has an SD card slot and a headphone jack...and a 5500mah battery. Will never go back to Samsung again

I gotta say, sometimes I miss my fully customized LED on my blackberry back in the day. It could be in the bottom of a gym bag and I’d still know if I missed a Google Talk message (green) or a Facebook alert (dark blue) or an email (light blue), etc etc etc.

Off topic a little but I stop most of my messaging app to notify me. And my life is so much more peaceful. I told everyone when they connect with me on any messaging app that it'll take time for me to answer. I'll read it when I remember to read it, which I do like once or twice a day. They adapt to that and if it's really important they'll call.

With OLED, your entire screen is an array of possible LED notifications :)

iPhone = Settings / Accessibility / Audio Visual "LED Flash for Alerts" (at the bottom)

I didn't know I miss those LED notifications until now. Thanks :(

My guess it is cheaper to do software features rather than a physical led .. cutting costs at every corner

The whole front of modern phone is a display, there's simply no space for a notification LED.

I get so many trash notifications it would just be on all the time and I'd turn it off.

When you have questions like this, the answer is almost always money.

For this particular question, it is money - the cost of the LEDs (which is of course minimal, but multiplied by millions of phones), but also manufacturing (need to have a hole in the case to let the LED shine though which can let water ingress into phone). To make those holes water tight would add more cost so instead they decided to use the screen itself as the notification method. I think Motorola's implementation of this was the best - they had their always on display to show notifications and a single tap would let you see what the message was even if the phone was locked.

I forgot all about notification LEDs when I got a smartwatch

I'm pretty sure it's just to cut costs / complexity / part counts in lower end phones, and higher end phones will use an always on display.

Though worth noting that the Nothing Phone 1 & 2 include pretty snazzy LEDs on the back that are used for notifications amongst other things.

I'm guessing that with everything they cram into those things nowadays, every last nook and cranny is valuable space to be used.
A little blinken light is probably not high on the list of features competing for that space.