Depends on what state you're in. Most still allow self-defense.
Yeah, my state goes by the 21' rule last I knew. Started off with a fuss because the police were shooting people who had clubs and knives. The police gave plastic guns to some of the state legislators and had them try to simulate defending themselves from attackers inside 21'. The legislators quickly found it was shoot immediately or the attacker with club or knife had the advantage. The 21' rule was quickly applied to concealed carry too.
One thing rarely mentioned, concealed carry often saves lives on all sides. There is a story of an angry mob I negotiated with elsewhere in this thread. There were a handful more times when had I not been carrying a firearm the disparity of force would have left me no choice but to act first. The reason I bought a carry gun to begin with was that I almost had to use a five pound steel hook to defend myself one night. The would be attacker would have been just as dead but I would have been in more trouble. I learned from a case where a friend had to defend himself and his family, if you kill somebody, neatness counts!
Another thing, "Shall Issue" states are far safer. It was kinda funny, our vehicle is an extension of our home in my state, quite legal to have a firearm in your vehicle. However, the day shall issue went into effect in my state, roadrage incidents went down over 90%! An armed society really is a polite society. Much more recently, I had a minor altercation with two young men. One was middle sized, the other was the biggest man I have seen in decades. The giant was the one pulling back. If this crazy old white man wasn't intimidated he was probably carrying, ready, and willing to shoot somebody!
Just the fact that the average person could be carrying is a deterrent to crime and violence.
Hu