Fair enough. And agree tone is often hard to get in the written word. My capital letters are not yelling they are just emphasis. It just takes far longer to type than to say and a 1 minute conversation takes 3 pages on the web and can be frustrating.
As to my own personal experience, a guy was threatening me with a knife while I was seated in the passenger seat of a car with the door open. He was actually leaning into the car. I jammed the knife arm with my off hand as I shoved the muzzle of my pistol into his diaphragm backing him up...( I had already put my hand on the gun as he pulled the door open). I brought the gun up to eye level got a picture perfect sight picture on his chest and took up the slack....during this I had to stop looking at him so intently to be aware of the street behind traffic him and whether there were cars behind him or not. And I remember thinking "so THIS is what tunnel vision looks like". I gave him the option and he decided he was late for an appointment elsewhere and made his retreat. In this particular case , with background that was changing, a target backing away and me being only 20 years old at the time and not nearly as confident in my shooting ability as I probably would be now 21 years later a HARD front sight focus is what I used. SO I DO understand that and have experienced it for real.
Fast forward to more modern times when I was at NTI and much more confident in my shooting ability from years of practice, an IDPA Master ranking, multiple match wins in different disciplines and 100s of hours of FOF training. At NTI I scored a 100% hit ratio in the FOF evolutions and was not "killed" in any of them and I simply looked over the top of the gun for close up "reactive" problems.....one of which was 3 on 1 in low light. We were armed with J frames that were issued to us and not exactly "modern " pistols with good sights. So we might argue that if the sights are barely usable you probably won't use them? Who knows. All I know is that the rounds went where I directed them.
On the other hand I used a picture perfect sight picture in a more proactive situation at NTI where I took out 3 "terrorist" role players while armed only with a battlefield pickup J frame I took off a "wounded" security guard.. I used cover , architecture , surprise and precise trigger control and was able to prevail against them. So I do get it and I do know the difference in checkers and chess. And I'm not trying to beat a dead horse. I'm just saying that in CLOSE distance shooting where we are 4 yards and closer in a reactive "under immediate danger" situation I feel pretty confident in my own ability to get the gun up to just below my eye line but not have to have a picture perfect sight picture and still deliver accurate fire (think Point Shoulder). Is a solid sight picture BETTER???...OF COURSE it is... if you can get it. But it may not always possible due to distance and immediacy of the threat, low light etc.
So my answer to the OP remains...yes...with enough experience and confidence you can step away from picture perfect sight picture and still deliver accurate fire within the correct distance envelope. But it is not something that the TYPICAL CCW guy is going to be able to do without a LOT of work. They need to MASTER grip, trigger control AND using sights and only then step away from perfection as necessary. I do dry work and draw work every day and shoot every week and do FOF every month. So I'm not the typical gun carrier. ALL I can speak from is my experience and in my experience it is possible.