[HeyLaughingBoy]

My guess (based on living on a dirt road which gets everything in a vehicle coated in a layer of fine clay dust) is that it reduces the number of water/dirt ingress points so the door lock lasts longer.

I've had to take the door panels off two vehicles now to clean dirt out of the locks to get them working again.

[tomrod]

25 year old cars with mechanical keys do fine on dusty roads.

[HeyLaughingBoy]

How about my 19 year old car with a mechanical key, which happens to be one of the vehicles I mentioned having to clean?

[tomrod]

Sounds like you had a run of bad luck rather than something systemic.