This is all al fine example of "boy things are really good, but they're far from perfect"
In the Benham episode, the engine event was NOT completely contained - some fragment smacked the fuselage - but in a place that didn't rupture a window or the skin, and didn't destroy a stringer or longeron. Had it hit higher, or lower, would have been much worse. Had it hit any part of the tail would have been much worse.
There was a crash of prop cargo plane (I wanna say an HC130) where they lost a prop blade. That alone wasn't a problem, except it made so much vibration that other engine parts failed, and one of them destory a longeron, and the airplane came apart. So the Benham accident was maybe closer to utter disaster than it may appear - which is chilling given how difficult it was for a very well prepared crew to deal with the incident.
The Benham accident was over open ocean - very low odds of hitting anything. The Denver incident (just a couple weeks ago) dropped heavy objects all over populated areas, and by great luck no one on the ground was killed, but vehicles were destroyed, etc.
And on 22 Feb in the netherlands a 747 engine failed, dropped some debris, and people in the ground were injured.
Yes, all of these jet failures were "good" in the sense that they caused far far fewer fatalities than crashing the plane into a large crowd, but they were all super perilous. And the SWA accident killed a passenger (sucked out the window) - zilch the crew could do.
So just because something has become very good does NOT mean it should not be subject to constant vigilance, or it that it cannot be even better.