Because we don’t need to. However, some competition stages require us to lean hard. Competent competition shooters have the skill set to lean. In my experience, when they are put into a environment where they have to lean, such as a “tactical” class - they lean and can hit things while leaning.
Which is why many competition formats include moving targets in their stages.
You get good at speed by pushing yourself to the breaking point of speed. You don’t get faster by staying the same speed. Those types of training are critical to becoming faster.
I am a competitive shooter and I am able to comprehend the difference between a cardboard target and a human target. The idea that a competetive shooter would only put two shots onto a human target and then unload and show clear is… yeah - that’s just not gonna happen.
Furthermore, there is complete merit in showing restraint in your shooting. Over 50% of violent encounters involve more than one attacker. It’s possible to empty a mag into a person before they hit the ground - and now you’ve got an empty gun and more attackers to deal with.
What you need is fast visual processing. Assess your own shooting, where your shots are going and what is happening. You practice that by shooting lots and engaging reactive targets - something common in the competitive and tactical world.
Tactical shooters love to obsess over cover. From all of the CCW/civilian gunfight footage I’ve seen, cover is an option in less than half of them. From my observation, most civilian gunfights start in the open as people are engaging with each other and they are over as quickly as the magazine gets emptied.
IMO - being able to get your gun into the fight and quickly and accurately empty it into an attacker is the single most important skill a conceal carrier should have as the gunfight will be over before anyone could get to cover.
My point is - being a blazing fast and accurate shooter is a greater asset in a gunfight than being a mediocre shooter who knows how to use cover.