So, just to make sure we're on the same page.

A striker fired semi-auto that does not have a manual safety as such still has safeties. All have internals that prevent a 'bumped' firearm from discharging under most circumstances. I.E. you put one in a paint mixer and turn it on it shouldn't fire. If the internals become worn then they can fail, and as anyone who has worked around machinery knows, stuff happens.

Glocks have a small tab on the trigger that must be pressed for the trigger to be depressed. Kinda counts like a safety.

Pistols with external safeties have some kind of lever or other device that interferes with the hammer hitting the firing pin. In a 3rd Gen that is a robust bar, in a 1911 that is a tooth that engages.

Now accidental discharge is an interesting term. IF you mean I drop the gun and it does bang, that doesn't happen much with non-messed with modern weapons.

Most 'accidental' discharges I think have been shown to be a situation when the trigger is pressed. The story above about the deputy, well I'd be interested to see what they figured pressed the trigger.