Speaking of opinions, Iāll go ahead and share mine.
Of course boxing can be an effective method of self defense. Anyone saying otherwise doesnāt know much.
Iām no boxer, but I have an observation to make and it seems that in six pages of discussion, the real issue hasnāt been addressed. Boxers use wraps and gloves to protect their hands. This makes sense because they pound on a heavy bag and on pads a lot, and they need to keep their hands safe so they donāt disrupt their career with an injury. This holds true for training and for competition. The hands and wrists are wrapped for support, and they wear gloves for further protection of the hand.
The problem is, the wraps and gloves change the structure of the fist and can hide minor flaws in technique and protect the hand from injury during a punch that, had the fist not been wrapped and gloved, would have caused an injury. So if a boxer ALWAYS uses wraps and gloves, they may never realize there are flaws in their technique, and furthermore they may never develop the conditioning to withstand the impact without that protection. So if they ever need to punch someone in self defense, without that protection, without wraps and gloves, it is possible they may land the punch with poor alignment and poor fist structure, and they end up with a broken hand.
The obvious solution is to spend time hitting heavy bags and pads without wraps and gloves. Do it bare-handed, learn what it feels like to punch without protection, understand the alignment and how little errors can lead to injury on impact. Understand that you likely cannot punch as hard without that protection, without risking injury. Develop the conditioning to handle a bare-knuckle punch.
So this isnāt a problem with boxing, but rather a problem with the likely training habits of competitive boxers. Those training for competition will follow the best practices to that end, and of course that makes sense. But that may not be the best training approach for self defense on the street. Of course this isnāt difficult to overcome with the addition of even occasional practices to deal with those issues.