To increase. The disadvantages, and some advantages.
Classic 4WDs are often raised higher. Increase the benefit of? That is very easy with getting in and out, but it is usually not done for that. Another advantage of increasing: on the road (and most 4WD kilometers are made there), the driver has a better traffic overview.
The basic approach is of course that an increased 4WD more 
ground clearance. But don't be surprised if the driving qualities are completely dredged after mounting an elevation set.
The stiffness of the (front) springs is important and some kits cause vibrations due to the changed angle of the universal joints. The steering characteristics and handling can change dramatically.
In addition, a raised car can cause a degree of body roll in the turns that until now was only known by 2CV pilots with ADHD.
Ask a specialist for advice about purchasing an elevation set.
There are sets on the market that are absolutely qualitatively inferior.
Rancho and Skyjacker are the names of a few serious providers in this area.