Although I currently have only 1 logical volume, and all my PV's are currently a part of it, that's not necessarily how things will always be. I intentionally partitioned most of my disk into ~2GB chunks like this, so that I can have a pool of 2GB PV's which I can throw at whichever LV needs it, and thereby rid myself of future space constraint issues I've run into in the past with traditional partitioning.