The drivetrain doesn’t have a place to live. The nose of a truck holds the guts, freeing up space for load in the other half. Moving the guts to a cab-over would shrink the available engine size. Having all the power train to one side would require entirely new engineering to have 2 double length axles with no counter spinning force, so torque on the frame would twist the chassis up at the far point like a lever.

Or it would be underpowered to prevent it, effectively a kei truck engine in a full sized truck body. It is going to work much harder in some way to be as successful as existing trucks.