I know this is a widespread failure mode on street lights or exterior LED lighting, and I’ve been seeing more and more purple LED street lights out in the wild, even tho I haven’t really seen them in 2021 in our area. I haven’t seen household LED bulbs turn purple, are they affected too?

Have you’ve seen any purple LED screw-in bulb? I believe I saw the first purple street light in 2024.

I thought the same thing! Apparently, some household lamps are doing it, I have seen a few picture floating around LG of exactly this. Never seen it in person, but I will take a picture when I do.

Here is @Maxim's cool picture of some Cree bulbs that turned purple:
https://www.lighting-gallery.net/gallery/displayimage.php?album=lastup&cat=14217&pos=38&pid=261019

Yes they indeed are!😀, I have a 2 watt filament lamp at the top of my stairs that runs 24/7, it’s slightly noticeable by eye, but in the photo I have turned the colour saturation up so you can clearly see it👍

I have seen the opposite thing happen once

The diffuser material on the LEDs ("1W"/"3W" style gull wing LEDs) degraded from the intense blue content in the light, discoloring to a burnt brown color and making the light color shift to some orange-ish color as well as drop in brightness

This happened in lamps that been some 12+ years in service though, most lamps just dont last anywhere this long

The "turning purple" is just one particular failure mode on which just the particular LED design used in the streetlights was prone to. I don't think that style is used anymore, not just because of the tendency to turn purple, but also because the LEDs are extremely vulnerable to damage during assembly.
For domestic LEDs a broken bonwire failure (LED chaotically flickering or cycling, then dying, often with a noticeable internal burn mark) is the most more common failure mode these days.
It seems most problems become solved, except the bonwires. It seems there is no principal solution except some minor optimizations here and there.

The principal solution is to not "optimize" the lamps by reducing the heatsink size and number of chips in a lamp of the same power rating