Perhaps also the wing aerodynamics is better these days, so less complex flap is required to achieve acceptable speed on t/o and approach?
A good example would be A320 vs A321. The latter has (almost) the same wing as the former, even though it’s a heavier airplane. To keep the t/o and approach speeds in check (as well as the speeds) it has a more sophisticated, double slotted flap, compared to the original.