In the real world, the biggest time eater in the draw cycle is in the OOD part of the OODA cycle.
Since a fair number of folks are likely to be baffled by that statement, I explain.
The OODA cycle is known as "observe, orient, decide, act". Details can be looked up, but the essence of the thing is that working backwards from the actual taking of action, you have to Observe something going on in your environment, Orient yourself to the idea that you might have to take some sort of action, Decide what action to take, and then, finally, you get to the part that timers actually time: the action itself.
In the practice/range/idpa case, sure, you can draw < 2 seconds, but only because you've already Observed that you're on the range, Oriented yourself to the fact that it's appropriate to fire upon cardboard targets, and have actually decided to do so when you hear the BEEEEP! (1.x seconds later) BAM!
If you spend some time looking at videos of actual danger nearby, you'll see that danger gets a free hand for like, 5, 10, 20 seconds or more before people start reacting.
Roomfuls of people don't die because of extended capacity magazines. Roomfuls die because they mostly sit around going "duh?" in those critical opening moments of danger.