There is also much more wing than is strictly needed to keep the plane aloft and stable. They're optimized for low fuel consumption at a design-specified cruis

There is also much more wing than is strictly needed to keep the plane aloft and stable. They're optimized for low fuel consumption at a design-specified cruising altitude and speed, with variable geometry, so they can still take off and land at lower speeds near ground level. From a certain perspective, the flaps give the plane redundant wings. One pair for low and slow, and another pair for high and fast.