This is a hard question to answer, but I'll try to boil it down to this specific firearm. Many handguns, like all Glocks and many Sigs, these days are "striker fired," meaning there's an internal hammer that strikes the hammer versus an external hammer. Internal hammers are more complicated than external hammers, and that includes, in the case of Glocks, two built-in safeties internally that would prevent misfires. The only way they would fire is if the trigger is pulled. Period.

There are no external safeties for the operator to engage with these handguns. They will only go off the trigger is pulled - so drops should not set it off, nor the actions in the video. You have to intentionally pull the trigger for the gun to go off, which is the ultimate last word in safeties.

There are still semiautos with external safeties hammers, the most famous being the 1911. These are what's called single actions. The trigger weight (amount of pull on the trigger) is relatively light, so they have an external safety for the operator to engage/disengage.

I personally prefer single actions, hammer cocked, safety engaged, but this is always a very, very personal preference by people that carry. I own Glocks, but I would not carry one because of the lack of external safety, however, I would never criticize anyone that does. This is 100% strictly boils down to what the person is comfortable doing.

> Glocks, two built-in safeties internally that would prevent misfires. The only way they would fire is if the trigger is pulled. Period.

Two built in safeties, plus a half-cocked striker instead of fully cocked like Sig. Another big difference is that one of the safeties is a physical thing sitting in between the striker and the primer. The equivalent on a sig 320 is a physical thing sitting in front of a lug attached to the striker, not actually in between the striker and the primer. That makes it a single point of failure, because if the lug shears off of the striker, the gun immediately discharges.

The big failure case for a Glock is something (drawstring, etc) getting into the holster and pulling the trigger. If you commit to never holstering without going really slow and shining a light down in there to verify nothing is getting at the trigger, it's safe. Which works if you just never take it out of the holster except at the range. Remove the holster and gun as a unit, stick holster and gun together in a safe, etc.

The absence of external manually activated safeties is really orthogonal to whether it’s striker fired or external hammer fired. There are countless guns that have external hammers with traditional double action or single action modes, but still lack an external safety. This is true of many many SIG and HK models.