I got rid of the tubular Jack stands many years ago.
I now have 6 of the "better ones" and never get under a vehicle unless at least one end has TWO jack stands backed up by a floor jack that has the pressure slightly released.
When I want both ends of the vehicle raised up I do one end and then the other
AND I use 4 jack stands.
I never use two jack stands on one side as shown in the failure picture.
When I was a kid - before jack stands I used big wooden blocks - not stacked.
My dad would have shot me if I tried to use cement blocks.