There's a line of thinking in the gun world today, especially but not exclusively among those new to handguns, that since most personal defense encounters occur within 15 ft, it's pointless to practice any further. Their standard is man sized target at 15 ft.
While there is certainly a difference between the mode and manner of personal defense training, competition shooting, and handgun hunting, I believe accuracy is to be the foremost consideration. Especially considering that there is much more at stake with the accuracy or inaccuracy of your shot in personal defense than there is in competition or hunting.
Personally, I generally carry a Browning HP. While many folks today are opting for pocket .380's and other such guns. Certainly nothing wrong with these guns, but realistic accuracy is far less than is possible with a full sized auto.
In other words, there's a lot of variables. I tend to think that the farther the distance that you can accurately place shots the better equipped you are. Of course speed is a primary consideration also. Speed is worth nothing without accuracy, and accuracy isn't worth too much without speed in defense handgun shooting.
Accuracy requirements should be tailored to a shooters skill, (don't set up a new shooter at 25 yds,) it will only frustrate. Yet the requirement should also progress with the shooters skill. When accurate hits are achievable at 15 ft. move back to 20 ft. and practice to maintain speed and accuracy.
Sorry for the long post. Hope some of it was useful.