Laws of UX
Pareto Principle
80% of effects come from 20% of causes. Focus on the 20% of features, flows, and pages that serve 80% of users. In accessibility: fixing the 6 most common WCAG failures addresses 96% of detected errors.
In plain terms
A small share of causes drives most of the results — fixing the handful of most common accessibility issues removes the bulk of problems.
Why this matters
A small set of issues causes most of the harm. In accessibility, fixing the handful of most common failures — contrast, labels, alt text, keyboard — clears the vast majority of real barriers, so start there.