The idea of locking hubs is having the ability to drive on paved roads
and highway, where most people to 99% of their driving, with the front
differential disconnected from the wheels.
If mud is even remotely possible, you leave them locked. But the rest
of the time you drive, you leave them unlocked. I know when I'll be off
road in advance. Besides, there isn't much mud in the desert.
When I lived in the NorthEast, I only needed the hubs locked on a
regular basis during the snow season, December, January, and February.
The the other nine months of dry weather, I still had to have the front
differential working for no reason.
Speaking of Greece, I have a house in Greece, just outside of Athens
(Byronas). I have a tiny car there with a tiny engine. There is a tax
when you buy a car with an engine bigger than 1.8 L. This car gets goog
enough mileage with a 1.4 L engine that I dont have to worry about the
price of fuel.
With Greece's lack of super-highways (besides the one that goes to the
airport) and constant traffic, small engines are fine there. Besides,
Athens has a mass transit system almost as extensive as NYC. The busses
and trains cover the city well.
Where I live, in Arizona, there is no mass transit. Highways cover the
area well. Due to how spread out everything is here, everything is far
away. I drive 500 miles per week, so at $3 per gallon, I have to go for
every mile per gallon I can. I can stand the inconvenience of locking
and unlocking my hubs once or twice a month when I do go off road.
Saving wear and tear is nice too.
By the way, fuel prices in Greece proove that national politics have
little to do the price of fuel. Greece has always had a pro-Arab stance
in the world political theatre. Yet, they have always paid a lot more
for fuel than we do.