Those using a smartphone as an alarm clock, what happens in the middle of the night when you want to check the time? With an old-fashioned LED alarm clock, you can just roll over and glance at it. With a smartphone, do you have to pick it up and look at the screen? Because that sounds less convenient.
It is, but you trade that mild inconvenience for darkness when you don’t want to know what time it is.
That’s what I get for posting in a hurry right before bed time.
Not everyone has old phones. I either use electronics till they break, or sell them on eBay. My last phone sold for enough money to buy a fancy alarm light/clock. For any application I could use an old phone for, I could instead buy a specialized device that does the job much better, for less money than I get from selling the old phone.