With iPhones i think it's less about durability (and especially in the software department they were always great in terms of longevity), but more about repairability in case something does happen.

As far as lightbulbs go the issue with potential planned obsolescence doesn't go way just because of the swap to LEDs. First there are a type of bulb even today that use some form of filament and second the part that gets damaged is usually some kind of capacitor or other electronic part that gets run with too much voltage and too hot. Don't have time to watch it again, but i remember finding this video from a few years ago interesting.