The amount of current LED consume varies (due to varying internal resistance) with its temepture assuming voltage is kept same. Now, if your LED heats up, it's

The amount of current LED consume varies (due to varying internal resistance) with its temepture assuming voltage is kept same. Now, if your LED heats up, it's internal resistance goes down, it sucks more current and it heats up even more and this shortens its lifespan or can kill the LED instantly. A quality driver should handle grid fluctuations, limit the current (by varying the voltage) and LED should have enough cooling (to not disturb its internal resistance much or go above its optimal operating temperature) but often due to space and cost constraints, it doesn't happen. Some even use bad capacitors (low capacity, dries faster, low voltage rating so blows up when power surge happens) this induces flicker. Some use crap LEDs array which does not lit evenly, test for it by lowering the voltage if you see LEDs with uneven brightness across the array or grid, you've bad LEDs. Low quality components, insufficient design, poor QA, inability handle power surge (both grid and local ones) are primary reason for LED flickers and short lifespan Why they don't fix it? To minimize cost, which helps bottom line and boosts profit. Customer's experience with LED will vary (depending on if they've surge protectors or not or grid fluctuations, these are local to you and others might have different situation), so you won't instantly know from reviews or feedback online - which LED is good for you unless ofc you reverse engineer and figure out how it works even then you might not be able to figure out quality of components and degradation with time. Marketing/Sales can fix (hide?) lots of bad reviews and profits can be boosted regardless of underlying quality. Many customers won't pay more because they can't differentiate between quality. And everyone seem to agree that LED as a technology might not last forever, so why bother boosting lifetime/quality of current bulbs when they'll be replaced and an opportunity to make more money will come along? And when a new better bulb technology will come along, they all will blame their cost cutting induced quality / life issue on LED technology and then they'll move on doing same with the new technology.