The topically-closer page usually wins, because a link from a closely related page passes relevance that a link from a high-traffic but unrelated page cannot, though there is one condition where traffic takes it.

Relevance of the source is a real factor, not a tiebreaker. When a page about choosing running shoes links to a page about preventing running injuries, the link carries topical context: it tells search engines these two pages belong to the same subject, and it reaches a reader already in the relevant mindset. A link from your highest-traffic page, if that page is about an unrelated topic, passes far less of this contextual relevance, because the connection between the two pages is weak. The traffic is real, but traffic alone is not topical authority.

The condition where the high-traffic page wins is when its traffic translates into something the closer page cannot offer: meaningful referral clicks and engagement, or a genuine relevance that happens to come bundled with high traffic. If your high-traffic page is also reasonably related to the target, it can be the better source precisely because it sends real visitors alongside the link. The choice only tilts toward traffic when the visits themselves are the goal, or when the high-traffic page is relevant enough that you are not trading away topical fit to get them.

So the rule is: default to the topically-closer source for ranking value, and choose the high-traffic source when its visitors matter more than the relevance you give up, or when it is relevant enough that you give up nothing.

Faced with two candidate source pages, do not pick by which one has more traffic on the dashboard. Pick by which one is genuinely closer to the target’s topic, and override that only when the traffic itself is what you are after. The hunch says link from the popular page; the rule says link from the related one.