It's always been this way, even in the early days of metallic cartridges.
Each company hopes to capture a bigger share of an ultimately limited market by introducing thier own cartridges in their own guns, while others are introducing new cartridges just for the hell of it.
The market place makes the determination on what lives or dies.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.