Why that the LEDs inside automotive headlights would be driven harder than in general lighting? They should be driven the same.
They need as high intensity of the primary light source (the LED die) as possible.
Headlights are precise beam control optical devices, where the beam parameters, as well as light flux are strictly controlled by the regulations. To achieve that, the higher intensity the primary light source, the smaller the headlight could be. If you drive a LED by 2x higher current, the intensity will become nearly 2x higher, quite an impact on the total optics size. The efficacy penalty could easily be more than offset by the increased optical efficiency when the light source gets smaller and the car fuel savings smaller, more compact headlight assemblies. And the lifetime in the 5k hour range is more than the rest of the car (mainly the propulsion), so having it any longer won't bring any benefit.
On the other hand general lighting is more about diffuse light, running long hours, so very sensitive to efficacy (because electricity cost is the major operating cost contributor) and lifetime (replacement costs of the light alone are the second highest operating cost contributor). So the designs are more focused to get maximum life and efficacy.
At the end it is all about the cost. But not the cost of the LED chips themself, that is very small fraction. It is about the cost of the complete headlights to make and, more important, the cost required to incorporate them into the car and to solve all the implications related to that, like weight, aerodynamics, crumple zone design (the big holes in the from for the headlight have severe impact on the front structure) and also visual appeal for car buyers. The smaller the optics, the more flexibility is there to design the car, so the easier and cheaper is to design and produce it to still meet the regulations. So ability to achieve any higher intensity is saving a lot of costs at many places, as long as the headlights lifetime is not the limiting factor.
So car headlight the designs go for the highest intensity attainable for the given lifetime requirement, any longer lifetime has no benefit.
Vs the general lighting designs, which go after maximizing the efficacy and the run lifetime. Fitting into standard formats is just enough, any smaller makes no benefit.
In either case do not confuse the lifetime with premature failure rate (failures before reaching the rated lifetime). The later is a problem for both, so the related probabilities are also a factor steering the designs, but mainly the discipline at the production floor.
