Most personal defense gunfights happen up to 7 yards, so 21 feet.
I probably fire 50% of my practice rounds at this distance. I also practice a lot of double taps at the same range.
I also do not neglect the 30-50 foot range, but don't spend a ton of time there.
Once again, it depends on what you are training for.
VIGILIA PRETIUM LIBERTATIS
"The price of liberty is vigilance"
America is at an awkward stage. It's too late to work within the system, but too early to shoot the bastards.