Earlier quoted context omitted.
Not knowing anything about guns I would assume you would engage the safety when putting the weapon in the holster. Is that not true?
Many modern guns for personal protection do not have manually actuated safeties and instead rely on other mechanisms to prevent accidental discharge. For example, glocks have a "trigger safety." Without getting into minutia, these sort of features do a fine job of ensuring the gun does not fire unless the trigger is intentionally actuated. The reason manual safeties are going away is that for side arms, time matters…
I know there are a lot of people who share this opinion, but speaking as ex-military, I think it's quite disingenuous and dangerous. Real life isn't some old-fashioned Western film where draw speed matters. If an adversary is malicious, carrying a round in the chamber, and decides to pull on you, he has the element of surprise. There is no real-world situation where you are really just that much better at drawing and firing accurately that you will out-draw an adversary who drew on you first, with the possible exception of Special Forces / Navy SEAL types who drill it ad-nauseum and had 99th-percentile reaction speed to begin with. But thinking that ordinary people can do it is sheer hubris. Thinking you can do it from concealed carry is utterly laughable.
In a real world firefight you're either close enough where martial arts is relevant or you're not. If martial arts are relevant, then the guns are irrelevant. If you're further away, what matters is whether you can get behind cover, which will give you time to unholster your weapon, disengage the safety, and chamber a round.
You don't decide to carry a gun in public because you think it will save you if someone walks up to you from behind and decides to shoot you in the back. You do it for the times when gunfights are not resolved with the first shot. Responsible citizens carry their guns in such a way that prioritizes the safety of those around them before their own personal safety.