For sure, anyone who has seen some of the videos of drink carts and luggage bouncing off the cabin ceilings during crazy turbulence shouldn't have any questions about the utility of seatbelts in less than catastrophic events.... Which of course is the goal even in 'crash' landings. There are crashes where seatbelts would obviously be worthless, but in anything short of that, you'll be happy that you weren't in a box with 300 human shaped dice being shaken up.

I read this horrible post a few years ago where a PoS passenger didn't buckle up. So the car drove off a cliff, her body flew and killed people in the back seat who were buckled up. The driver survived since he was buckled in.

I was watching one air accident documentary where the plane dropped so hard that people who were unbuckled were launched into the ceiling and people found their phones and laptops in the back of the plane.

THIS!