But that's not the actual problem. Let's say the hold time is a random 10 to 20 minutes. What's your personal assistant supposed to do in the meantime?
They can't reasonably do anything that requires making calls or other real-time interaction in case the first phone call is picked up.
Even if they could make them do some non-time-sensitive secondary task while they're on hold on some primary task they'd still suffer some time wasted due to overhead & distractions.
