Deer are easy to kill, but at least where I hunt them, they are not always easy to find. They don't always just tip over dead when the gun cracks even with a well placed shot.
The 300 makes that job a lot simpler.
I agree with this statement. I've great respect for the .250-3000 and have taken several deer with it but, I noticed I wasn't getting the same results as when using my .300 on very similar shots so I retired it and went back to my .300. No rodeos since.
P.S. I even load my .308 and .30'06 to .300 Savage velocities because it just works!