Halfords ultra bright bulbs (90% ones) - question

[Tyson1980]

I have these installed on the car, I first put them on the car in February...

One went pop a few days ago and i replaced like with like. When i fitted the new one, it was noticeably brighter and the light traveled a lot further than the old one. So much so i thought i had the wrong bulb..

Is this what usually happens over time? Seemed odd since, the headlight is an enclosed unit...

If this is a daft question, I apologise in advance!