I’m in general agreement that no one with any training or sense intentionally walks into a gun fight with a pistol, if they have a rifle or carbine available.
Since the ATF has reversed itself and is now classifying braced pistols as SBRs that possible technical exception is about 10 days away from being eliminated.
My braced MP5 will easily and accurately engage torso sized targets out to 200 yards and the longer barrel gives the 9mm round a boost, with terminal performance on par with a similar weight .357 Mag round fired from a 4” revolver.
Removing the brace does reduce the accuracy. Still, with a well designed sling properly used to stabilize the pistol, a ”pistol“ like the MP5 can still be fired with good accuracy on torso sized targets out to pretty impressive distances.
The same is true with my braced AR-9. It doesn’t give up much in velocity to a 16” AR-9, but also isn’t much shorter or lighter, and is still too large and heavy to conceal carry.
The advantages of size and weight are why even a full size duty pistol will always be preferable to carry in a low threat environment than a rifle, carbine, or any of the “pistols” based on rifle/carbine platforms.
Similarly the greater weight and reduced concealability of rifles, carbines, and pistols based on rifles and carbines will continue to be used in only about 1 percent of gun crimes.