Rain in large quantities is not useful. Even in agriculture. That's a fact.
Today we found out that it does good to Milford Sound, one of the wettest places in the world, which gets to live under a nearly constant shower, accumulating to a staggering 6,8 meters of rainfall per year.
The positive thing is that it creates lots and lots of waterfalls running down the mountain faces. It even seems that mountains are sweating.