I once experienced a delay at Gatwick. Flight STD 3pm, info screens say go to gate xx which was right at the end of pier 4 (near the wavy wall) so a long way but partly using moving walkways. Looked out of gateroom window to see a couple of booked airline's aircraft but with no activity going on. Last call had been announced by gate staff. By 2.45pm some fellow pax started to enquire with gate staff if flight was delayed as no boarding announcement had been made. About 10mins later staff announced there was a delay but it shouldn't be long as the the crew allocated for the flight were transferring from another inbound flight. After about another 15mins a general announcement was made for all pax to return to the departure lounge. Moving walkways were moving the other direction so a very long walk. At departure lounge the flight details were missing from the info screen. They appeared again after about 10mins showing go to gate xx (different from before). I was told afterwards that when a flight is displayed as last call it automatically disappears from the info screen after a certain time period. Went to new gate and gate staff started boarding process soon after. Got on bus and then to aircraft but driver didn't open the bus doors as he was checking situation with dispatcher. It was obvious there was no crew on the aircraft. It was a very warm day and driver reluctantly opened the bus doors but we had to remain on the bus until the crew turned up. They eventually did and after carrying out their pre-boarding aircraft checks allowed us to board. Once all on the aircraft the captain announced that they were a standby crew who were called to do the flight as the airline had experienced some aircraft tech problems during the day. He also said don't be angry with the crew.
Clearly the ground handlers had no idea as to the cause of the delay but were only interested in getting the pax to gate on time. As for the airline operations team, they must have had some idea but were maybe struggling to find a crew to do the flight, so were not able to provide the ground handlers with accurate information.