Maybe they can be designed for thermal management, but very few of them really are. I'm also finding the LED is the most likely failure point, so I prefer to find fixtures with replaceable LED bulbs so I can install the ones I know to be reliable. That way the entire fan isn't junk when the LED dies.
Integrated LED fixtures are usually quite easy to fix when an LED actually fails. Check them all with a multimeter in diode mode and you know which one to replace.
