"Planes aren't fueled to capacity" just enough to get to their destination." not true, if this was true, every plane would be required to be fueled before leaving. This does not happen supporting that planes dont use alot of jet fuel. Plus if they only had enough jet fuel to get to their destination, what would happen if there was flight difficulty, they had to change routes because of weather, power, or whatever problems they might occur? So if that where the case, there would be more plane crashes cause they ran outta fuel. I dont think thats ever happened in commercial flight.

"I think they have dedicated pipelines supplying their fuel." this "popular" excuse would just mean there are dangerous pipelines underground between production companies and airports, there are not. if you mean these pipelines are just within the airport grounds as in there are huge tanks capacity just a mile away, we would see a jam of tankers unloading their supply every day, we dont see this ever supporting the idea that planes use far less fuel than we are told, with the possible that newer planes are just using electric power/batteries and air centrifugation technologies.