It is important that we study these planets for a number of reasons. The extreme atmospheric conditions and long seasonal timescales found in the ice giants provide a unique opportunity to better understand the physics of weather and climate. More fundamentally, these planets may also help us learn more about the formation of the solar system. Understanding why the bulk densities of Uranus and Neptune differ from Jupiter and Saturn can help us to better understand how planets formed and what processes shape planetary formation in general.
From a big-picture perspective, the ice giants are seen as possible representatives of a general class of planets that appear common across the galaxy. Studies looking at the variety of exoplanets discovered in recent years show that exoplanets with sizes roughly similar to Neptune are among the most numerous. By understanding the formation and characteristics of our local ice giants, scientists hope to better understand these vastly more distant planets and the processes by which they were formed.