H7 Bulb Lifespan: How Long Do They Last?

How would you estimate the lifespan of H7 bulbs?

I don't have any data on the burning hours, but with a relatively 'constant power consumption,' I have run the lamps for various durations.

Original VW factory-installed headlights: approximately 60,000 km (driving distance).
Acquired gas station: approximately 30,000 km.
Aftermarket OSRAM bulbs + 50%: approximately 20,000 km.
ALDI (brand new): approximately 10,000 km.

Question: Why did the original bulbs last so much longer? How can I identify long-lasting bulbs? Could there be another reason why my headlight bulbs keep burning out faster (while all other light bulbs are still the originals)?

Hello,

Experience has shown that these lamps provide 50% more light.
niemals die Lebensdauer einer normalen Lampe haben. What is also lethal.
For lighting fixtures, make sure the light is turned on and the front panel is closed!
If you value a long lifespan and aren't too concerned about extremely bright light...
Light, next time buy some from Philips (either regular or with... [the sentence is incomplete]).
30% more.

Greetings, H-P.

Well, this morning one of my 'White Light' lamps from Marktkauf (about 20 Deutschmarks for both) finally burned out after 1 year and 35,000 kilometers.

'They are noticeably whiter than the originals and significantly whiter than the Philips VisionPlus bulbs. The VisionPlus bulbs made hardly any difference to the originals in my experience. (For a Golf III with Hella clear headlight housings.) However, they were very expensive.'