A geometric scale (e.g. 1.25× or 1.333×) gives proportional jumps the eye can parse.
Define 5–6 sizes max. Pair with weight + line-height to amplify the hierarchy.
A landing page sets its headings at 14/15/16/17/18/19/20px — every level a pixel apart. With no real jump between them, the eye finds no anchor and skims straight past the H1.