Quite often gate staff don't know much more than the pax. They can only pass on what they are told, which is often not all that much. Don't blame gate staff but blame those further up the chain. Then again, such as the length of the delay, that cannot always be determined. If there's a tech issue it may depend on multiple factors. Just as one example, assuming the problem has been identified and the part is available, a repair might only take 10 minutes but sourcing an engineer (or engineers) during a busy period may take much longer. Yes, it's all very frustrating for us, the pax, but just as frustrating for the gate staff and the crew.