There seems to be a lot of confusion about sights these days so I'm going to try and shed a little light. I don't expect to convince those of you who already know better, but I know most PF people are open minded and want to improve their understanding.
Shooter A is a top level shooter who is capable of tremendous speed and accuracy with iron sights. Shooter B is another top level shooter and is capable of more speed and accuracy with a dot gun. Both are at the top of their field. Shooter A may never be as fast as shooter B, even when using a dot gun. Shooter B has learned to see and read the dot in ways that Shooter A just can't manage with all his years of iron sight shooting.
Shooter B may never be as fast as Shooter A when using irons. His years of dot shooting have made it harder for him to use the irons at Shooter A 's level.
Shooter C is an iron shooter, who is just below shooter A's level. When Shooter C picks up a dot gun, he exceeds Shooter A's iron ability. Shooter C knows that dots are different than iron sights and "see what you need to see" needs to be relearned and applied a little differently when dealing with dots. Shooter C may or may not ever be as good with a dot as Shooter B, who focuses on dots, but Shooter C can shoot both irons and dots at a very high level.
Shooter D is also just below Shooter A's ability with irons, but unlike Shooter C, D is unable to go faster with a dot sight than he can with the irons he is so used to.
Shooters E-Z, spend more time on the Internet then on the range, and will never have the trigger time or understanding of Shooters A-D. They think that their experience with dots or irons has meaning beyond a simple statement of their ability. The smarter ones will recognize that their ability is only a reflection of them, and not an unbiased accounting of their equipment.
Factors that can affect Shooters when switching from irons to dots include things like age, vision, physical conditioning, see speed, understanding of how see what you need to see means in each case. Also things like inherent bias or preference can play a role.
The TLDR version is that all things being equal, a dot is capable of more performance than Irons. Your personal experience, nor the experience of your favorite shooting celebrity does not change that.
Yes, there are grades of " dots", and some are higher performance than others.
To make this more personal, every shooter has things they are better or worse at. Travis has an amazing reload, for instance.
My wife says that my standout is how fast I acquire a sight picture and see what I need to see. If this is true (she may be biased), then it helps explain why I see the performance differences that I do from one system to the next. If someone else has amazing splits, but doesn't see the way I do, then they may not "get" the difference in systems the same way. I'm sure you can think of examples in your own life.
If a tree falls in the forest...