Certainly, with enough practice, shooting from the same position on level ground, at reasonably close ranges, point shooting from the waist can work.
Have you found that you can do this reliably at different angles from your body, or at different heights instead of on level ground?
IMHO, competitors that win matches, do not point shoot from the waist. They bring the gun to eye level, and even if they are not using the sights consciously, they are able to use the sights (or the profile of the firearm) to index the gun on the target subconsciously.
I have known some fine shooters who can hit very well without sights, but they are just using the profile of the gun as a substitute for sights. Shoot enough, and how the firearm has to be pointed to hit become part of your subconscious, and is done mostly automatically.
It is very difficult to transition point shooting from the waist to many situations, such as shooting from behind cover, because accurate fire then becomes dependent on body positioning, which is unreliable in dynamic self defense situations.
I am not saying that accurate point shooting from the waist is not possible; I have seen it done. It is a technique that is more limited in its application than is interposing the gun between the eye and the target.
No, I don’t shoot from the waist, in matches, LOL. I was just stating what can be done with practice and concentration. When shooting for speed, lock on the front sight, as I said, pretty much forget the rear one. When I start with the gun low, or from a draw, I pick up the front sight on the way up, then lock on the target. I don’t think I use the gun profile for aiming, fast shooting to me is pure muscle memory, and damn near unconscious at this point in my life.
I shoot about 300 rounds a month these days through various .45’s, I am 55, eyes not what they were, but honestly shoot better than I ever have.
When shooting fast, the vertical POI will be largely related to the grip angle. For example, I will tend to shoot high with a DA revolver, a gov’t .45 grip angle, not a problem.