The math is pretty intuitive; every second you're burning is another 9.8 m/s of delta V you have to spend counteracting gravity instead of slowing the craft dow

The math is pretty intuitive; every second you're burning is another 9.8 m/s of delta V you have to spend counteracting gravity instead of slowing the craft down (minus air friction) so minimizing deceleration time cuts your fuel expenditure massively. It also means you have to carry less fuel so you weigh less and you spend less fuel for the same acceleration. It's the inverse of the rocket equation really, less mass is easier to slow down and you waste less energy (ie fuel mass) decelerating faster.