I’d much rather this member of staff being used for a single rider queue on any of the coasters
This is such a ridiculous comment.
Most of the single rider lines at AT never even had an extra member of staff to operate them. It was just another queue that you entered, and a ride host would open the gate when there was a spare seat.
AFAIK They were removed because people abused them so much. As a user of the Ride Access Pass, I've seen this firsthand on rides like Dragon's Fury where the RAP queue is right by the single riders, so often you'll see full families of 4+ in the SRQ when they really should be queueing normally, sometimes they even let them all on the same car which is ridiculous. People see it as a free fastrack.