Are they in fixtures designed for incandescents? "Boob lamps" for example are highly efficient LED bulb destroyers, since they don't breathe, and the bulbs overheat.

More anecdata, but I had ~20 lights, of various quality (many Hue, some cheaper Home Depot specials) in boob lamps that survived at least 11 summers in a New England house without AC. Still there probably, but I moved out so I can only vouch for 11 years.

That seems especially lucky. I'd guess they're slightly different in design or installation from the ones in my previous apartment (also northeast) that killed several and various LEDs... They stopped dying when I had the idea to shim the cover and create some ventilation. Mine were fairly heavy glass domes and had some insulating material against the ceiling.