Just made a super strong and sturdy workbench that breaks down into almost no space in a matter of seconds
2 sheets of 2' x 4' x .75" ply glued together
2 2x4s about 4' long
2 sawhorses (the kind with the slots for taking 2x4s, rated for 1000 lbs)
Put a little too much on top and the hinges buckle, if they move even a little bit from the side, the legs twist and bend out of shape.
Seen it happen hundreds of times.
Get the /diy/ kits with the metal hinges, or build them entirely from 2x4s. Or better yet, build an actual work bench. There's thousands of simple designs on the internet.