What is advantage of creating elements that disappear in a flash?
Researchers are looking for the Island of Stability, a predicted group of heavy nuclei with halflives in the minutes or even days. 

While we have some understanding that certain nuclear configurations and compositions are more stable, we are currently unable to reliably to a priori predict the stability, the half-life, or even the decay mechanisms of a nuclide. Thus, when a new element or isotope is produced, no one knows how long it will be around. Every time a new nuclide is produced, observations of its decay help refine the models of nuclear stability and decay.

The Island of Stability is believed to be centered around 120 protons and 180 neutrons. Element 118 $\ce{^194Uuo}$ has been produced, and while its most stable isotope has a half-life of only 0.89 ms, it is very close to the island of stability and there may be a heavier, more stable isotope of $\ce{Uuo}$ out there. 

As in many areas of pure science, the benefits to society (or even other fields) may not be evident except for those few who are actually doing the work. The outcome of pure science research is knowledge and information. Consider, for example, that research on cathode rays led to the development of the television decades later. 
The scientists studying cathode rays likely could not even envision their work being applied to the projection of moving pictures (especially those transferred over the airwaves as radio signals), as such technology did not exist or was very new at the time.