It made sense when HDDs were universal, it provided a quick check for a common cause of major slowdowns (you would then go hunt for the source of the IO).
Also on most cases you can / could just not plug that header in. Not an option for external drives tho.
You didn’t even need a light, you could hear the disk.
Such a missing feature honestly. You could tell if the program had actually crashed or if it was running still. New macbooks should play drive noises through the speakers like new Mercedes do with engine sounds.
I'm actually thankful for the coil whine on my GPU because I can tell if it's still running my compute tasks. I've even started being able to pick up on parameter misconfigurations based on the sound patterns.
They were amber, and quite dim. Just enough to notice if you were looking.