[jsjohnst]

The “savings” is entirely due to weight. More weight requires more fuel. The single biggest cost by a large margin in the life of a commercial airline jet is fuel. Increase fuel efficiency by even 1% and you save the airline industry billions.

Source to backup the claim of the scale of worldwide airline fuel usage: https://www.statista.com/statistics/655057/fuel-consumption-...

Source to give you an idea of how much US airlines pay for fuel: https://www.bts.gov/newsroom/us-airlines-january-2023-fuel-c...