"Timing" how long it takes in order to draw and accurately fire on a threat target has a lot to do with the conditions under which it's happening.
On the training/practice range you're
expecting to shoot, probably know
how to identify the threat target(s) from the non-shoot targets, the
safe background has been determined for you and the emphasis is on the task at hand (meaning you're not otherwise engaged in actual activities far removed from drawing and shooting guns).
Also, and this one matters ... you're
not at imminent risk of serious bodily injury or death by the "attacker" threat target. This can change things for a lot of folks, especially folks who have never faced serious danger.
Then, there can be a difference between just trying to deal with the effects of physical (muscular) stress, versus trying to overcome the unwanted effects of a hormonal fear response.
In one manner of thinking, thinking the answer lies in the isolated (to the static range) measurement of draw speed when it comes to a successful use of a handgun, is kind of like trying to measure someone's speed and ability to punch a bag, and using that measurement for predicting how successful they might be in defending themselves.
Will they react quickly and smoothly .... or will they experience the freeze part of the freeze, flight or fight psychological reaction?
Will they be able to unconsciously, and effectively, draw upon their static "training" when in the midst of a fear-driven hormonal response?
If someone is just looking to improve, smooth and quicken their normal draw/presentation? Lots of folks have already offered some normal observations about a desirable "average" timing goal ... mechanically ... meaning being able to draw and make an accurate hit, at 5-7yds, from under actual (realistic) concealment garments, using a normal carry holster, within 1.5 seconds.
In the "plainclothes/street tactics" class I attended many years ago, the students (all working cops) were told that being able to consistently get a solid, accurate hit on the threat target, drawing their working guns from under working concealment garments, ought to be able to happen in no more than 1.5 seconds, and faster was better (as long as accuracy and personal weapon handling safety didn't suffer).
It was offered as a goal for the average working cop, of average shooting skill.
Just looking to measure "sheer speed" of a draw, presentation and firing can be a distraction, or even a hindrance, though. Some folks find themselves ending up using a timer to measure how quickly they can make mistakes.
Learn and train to develop the skills. Learn to do it smoothly, and then work to do it smoothly
consistently. Speed can be the consequence of proper skills development.