That factoid is from a decade or two ago, when clear air turbulence was a lot rarer. Nowadays, due to global warming, turbulence coming out of nowhere is more common, and on occasion results in unbelted passengers being thrown into the ceiling and severely injured.
If you follow avherald.com for any length of time, you'll learn that 1) the vast majority of aviation incidents are completely benign, and 2) the vast majority of injuries aboard airliners are caused by passengers not wearing their seatbelts. The seatbelts aren't there for the once-a-decade crash; they're there for the once-a-month strong turbulence event, which the airplane itself will barely even notice.
In the event of catastrophic damage leading to explosive decompression it should keep you from being sucked out into thin air. Like if the roof tears off like that one time. Or that Boeing thing. Or that other Boeing thing. Or that other other Boeing thing.
Crash survival statistics are actually quite surprising. Like, you have higher survivability odds in the back of the plane -- cause everyone in front of you is your crumple zone.
Stupid question here, I guess, but why isn't there a system to potentially deliver commercial passengers and crew to the ground in case of a crash? Military jets have ejection seats and parachutes, so why don't we have at least something required for commercial aircraft in the same vein?
Is it the money that it would undoubtedly require?