In the last few years I have purchased a pressure cooker and an air fryer. They both waste electricity by having an off light. Furthermore they act like red nightlights and my kitchen has an eerie red glow at night. What is the actual purpose for off lights besides to waste electricity?
Off lights let you know if it's broken. If it's on, it's obviously working. If it's off and the light is on, it's getting power. If it's off and plugged in, but not displaying the light - that indicates it's broken or not getting power.
The power draw from a single LED is nearly negligible. If it's a heating appliance, for example, it's several magnitudes more wasteful to turn it on, just to see if it heats properly. Even with other electronics the LED quickly tests functionality with almost zero power without having to power up the entire system which would use a ton of energy, since it assumes it is about to be used for its purpose. It can also be an early warning of failure, I wouldn't use a heating appliance whose off light failed, because if the electronic failed, turning it on could hurt the whole house circuit or further damage the appliance itself. The light is a quick “hey, I need service” warning. Just like cars, those warning lights have meaning and use, they aren't just a decoration.
That makes no sense to me. Why not have an on light instead? If the light is on, and the device is operating as expected, that's good. If the light is off then it has no power or it's broken. If the light is on and nothing is happening, it's broken.
If the light is going to be annoying when the device is on, then turn it off after a few seconds.
I have a monitor that does that (but in white). It's in my bedroom. I had to use electrical tape like another commenter here mentioned - I left a tiny hole in the tape so I can see a faint light up close, but it's not making the room blink at night now.
For soundbars at least, the off light is there because there shouldn’t be any lights on while it’s being used so as not to distract the person watching tv. So the only way to know if the device is off is to have a light on.
You joke, but one time I got woken up by what sounded like a Chinese lady complaining about batteries, and it turned out to be the low power alert on the cheapo import soundbar.
My soundbar has a tiny blue light in the bottom corner that's on when the power is on and off when it's off. I've never been distracted by the tiny little blue LED while watching TV.
I figured the purpose was to warn us that these devices have been left plugged in while not in use, which is not advisable because they can become a fire hazard.
I visited my parents last weekend. They have s printer which has a wave light signal in standby - gradually switching from off to strong light and back. What my parents probably never noticed was the high pitch loud screech which followed the light. I guess the pitch was too high for my parents to hear, but not for me. So whoever designed that can go fuck themselves.