Yes, as they age, HID (High-Intensity Discharge) and LED (Light Emitting Diode) bulbs will dim, but this happens much more slowly than with filament type bulbs.

The answer would be a combination of the right filament material and using an evacuated bulb to prevent the filament degrading. But it took over a century to get a commercially successful lightbulb.

We tested the low-beam performance of single-filament (9003) and dual-filament (H7) bulbs from GE, Hella, Philips, and Sylvania, and PIAA's dual-filament bulb. We also compared their performance ...

You may have the wrong type of bulb, or it may not be screwed ... If it's a clear incandescent bulb, you can look at the ...