What is the goal of a rear-only lift?

Saw these two older Toyotas, a wagon and a truck/RV, which appear to have had their rear ends replaced with something much larger, necessitating a lift to the rear of the vehicle. Maybe for the RV this helps with axle load ratings - but I cannot understand why this would make sense on a wagon, as there have to be other vehicles with higher payload and/or tow ratings that would make more sense than this kind of conversion. Anyone know more about this?

 

You know how squatted trucks are indicitave of too few chromosomes? This is the opposite, too many chromosomes

 

That could be something as simple as air shocks. They were very popular back in the 70s to cheaply get clearance for larger tires for either the "look" or for additional traction for the cars with the big old V8s of old. I have run a few sets of air shocks myself when I was young. When I grew up, the affordable used cars for high schools kids were all the older musclecars.
Same look as your picture.

 

Those are hardcore herpers like me. Gotta see that road to see the little snakes crossing. Lot of birders in my area, they lift the front up to see the sky.