Why does steel quantity increase disproportionately for taller or longer-span structures?

Taller structures need heavier reinforcement in lower-floor columns and foundations to carry the cumulative load from floors above, and longer spans between supports typically need deeper beams with more reinforcement to control deflection and carry bending forces. This is why steel quantity does not scale in a simple straight line with area alone, and why the calculator treats storey count and structural type as meaningful inputs rather than afterthoughts.