Frame 5: Optimise for the common path

Ask: what are most people here to do?

Roughly 80% of effects come from 20% of causes: most users touch a small share of features, most attention lands on a small share of the page, most complaints trace to a few issues. The number is not the point — the asymmetry is.

Effort should follow it. Make the common task excellent before making the rare one possible. A checkout that is flawless for the standard order and merely adequate for the edge case beats one that is uniformly mediocre because every case was treated as equal.

Use it like this: when a design is getting complicated to accommodate a case, ask how often that case occurs. If it is rare, handle it somewhere else — a secondary flow, a support path, a manual step — and keep the common path simple. Complexity added for a rare case is paid for by every user on every visit.

Caution: this frame prioritises effort, never access. "Most users don't need it" is a valid reason to move a *feature* off the main path. It is never a reason to skip an accessibility requirement — that is Frame 1, and Frame 1 does not yield.