One aspect that's advantageous when you've got multiple non intersecting runways is when you have some sort of destructive emergency on departure, say uncontained engine failure. Having left a trail of parts over the departure runway you can of course simply reland on the other runway. Now if it's truly a single runway airport, of course you can get it all picked up (once the hot parts are cool enough) and then you can land back. But there is a case if you've GOT to reland ASAP then multi runways are better.