It depends. A lot of modern fridges use LEDs and have control boards driving them that cost hundreds of dollars. If the LEDs are out, the likelihood is not that the LEDs are dead, but that something much more expensive failed.
They do the slow fade-in effect when you open the door. That's got to cost something.
I, mistakenly, bought the refrigerator with LED lighting because I hated how old-style bulbs would turn on slowly in the cold. LED lighting should be instant I thought. Oh no, totally on purpose it was made slow.
PWM is trivial to implement, but you can sell it for real money as a feature. Or, in this case, a "feature". Not that it wouldn't be easier to just wire the door switch into the power rail for the internal lighting, but then it wouldn't also be able to play a cute jingle and tweet Elon Musk when the door opens.
Regarding slow starts - not that it's terribly useful to mention now, I grant, but most incandescent appliance bulbs can be replaced with compatible and much less temperature-sensitive LED ones these days.
My guess is that the LEDs are in series on a strip, and one burnt out.
The fridge manufacturer probably assumed it’ll always run cold (it’s a fridge right?) and overdrove them too hard to get just as much light out of 20 LEDs instead of 24.
Could bridge the faulty LED with solder to buy some time, and find a donor LED from a “burnt out” LED light bulb or whatevs and solder it in.
