30-odd years ago in the days of TAA/Australian & Ansett there were two 727's on the apron on a bloody hot, calm day in Alice Springs.
When the numbers were done pre-flight it was discovered by one of the carriers that they couldn't depart with the planned pax load. They put their punters over the scales, worked out what they could carry and get away using with actual weights and blasted off (almost literally in the 72!) successfully. For some reason the other carrier decided to go with the standard figures and a tiny wisp of headwind on 30.
I was having lunch in the tower at the time. This aircraft wasn't even thinking about flying as it went past the tower, got the nose wheel off in the last little bit of the runway and the mains somewhere in the red dust off the end.
Alice Springs was closed for about half an hour until the dust cloud dissipated in the minimal breeze.
Do I think we'll have weight-based fares? Not in my lifetime but it may have been a good choice to weight the punters back in '85.