Car isn't "waiting for you" at a valet. It is "show up at valet, request car be delivered", which means waiting 5-20m, vs. taking a shuttle. No airport has sp

Car isn't "waiting for you" at a valet. It is "show up at valet, request car be delivered", which means waiting 5-20m, vs. taking a shuttle. No airport has space in dropoff/pickup to hold cars for more than a minute, so they wouldn't be able to do valet pickup based on arrival time.