I have been running COB LED headlights in various vehicles for about 5 years.
They are much brighter - no doubt and I would not go back to halogen. But.
I live in rural Cumbria and do around 40 miles a day on narrow lanes in a Kangoo EV, so I have the lights on all the time. I have yet to have a pair of lights last more than a year, so my guess is a mean time to failure of around 700 hours.
I am sure the LEDs will last 20000 hours, but not so the cooling fans, the fans have no proper bearings, so they eventually seize, then the LED heat melts its solder connections and good night!
I have also had one set that caused radio interference.
Finally the LED is much larger than a halogen filament, so the beam pattern is less sharp. our local MOT guy fails it on bad beam pattern, so I have to keep an old set of halogens in the van so he can swap them out to pass the test.
Pete
(Still trying to convince meself to buy an MG)