Ex lumber grader, use my knowledge to piece out each table according to appearance and strength.
Uses F8/MGP10 - Australian standard 2x4s which are ⅛" thicker than ours. You cant buy these.
Because of the additional thickness, you get additional strength and rigidity, combine that with the longer screws that are glued in place, you got one hell of a table. (Just shy of 6' to make the ends nice).
Ive made more than a dozen, my first was made using standard 2x4s and had sat through 2-3 Washington summers and winters, I estimate had 800lbs sat at it on multiple occasions and didnt give out and then I moved away and left it behind and know not of its shape!
So these being thicker, glued screws, longer screws, and more experience into them, there's no reason why without proper care and maintenance each year it wouldn't last double the store bought pine rubbish.