It’s probably the amount of use those lights get. Theoretically it should last longer.

Things to check:

• Is your dimmer from a reputable brand, or unknown Chinese origin?

• Is your LED bulb compatible with dimmers?

If there is a problem with the dimmer it would be hard to diagnose without an oscilloscope.

Chances are its a dead capacitor on the LED’s driver board. LEDs last for ages, but manufacturers build in planned obsolescence through shitty support components. If you have a multimeter with a capacitor test function you could rip the driver circuit out and test them to confirm.

Other thing to check would be to make sure your lighting circuit has all the lights connected in parallel. Assuming you have more than one bulb on that dimmer, if they are wired in series then the first bulb would be having to handle the current draw for all subsequent bulbs. I imagine if this was the case it would be burning out pretty quick tho. You would know if they were in series though because all your other bulbs would stop working at the same time, and (im not an electrician) i dont think that this would be up to code anyway, so pretty unlikely.