The primary advantage of curing finishes and inks with ultraviolet lie in the speed at which the final product can be readied for shipping. In addition to speeding up production, this also can reduce flaws and errors, as the amount of time that dust, flies or any airborne object has to settle upon the object is reduced. This can increase the quality of the finished item, and allow for greater consistency.
The other obvious benefit is that manufacturers can devote less space to finishing items, since they don't have to wait for them to dry. This creates an efficiency that ripples through the entire manufacturing process.