Laws of UX
Fitts's Law
Time to reach a target = f(distance, size). Larger, closer targets are faster to hit. Make primary actions big and near the cursor. Applies directly to target size accessibility (WCAG 2.5.8).
In plain terms
The bigger and closer a button is, the faster and easier it is to click — so make important actions large and within easy reach.
Why this matters
Ignore it and people fumble for small, far-flung buttons — slowest and most error-prone for anyone with a tremor or on a phone. Big, close, well-spaced targets speed everyone up and directly support the target-size requirement.