How does this not leak?

All of my regular readers will no doubt recall my frequent comments on upper level decks, and the fastidious details and products needed to ensure these don’t fail. To me these are all cost and risk and liability with minimal upside. That sort of exchange feels pretty sour to me, so I won’t be inclined to do it. Certainly won’t be putting a warranty on it. Roof decks are a whole different level of construction execution, third floor issues, etc. without getting too bogged into detail, I won’t do it. Yet when I see it done by others I’m just baffled. Particularly when a roof deck is installed with dozens of railing bolts drilled through the tiny waterproof layer. After doing this you can’t even be assured the vinyl materials isn’t already compromised from day 1. Someone explain to me how this doesn’t leak, because I’m way too dumb to comprehend it.