Category 3 — OVERCLAIMED: factors marketed as ranking/visibility advantages where the evidence does NOT support it

Claim: Six overclaimed factors are commonly marketed as ranking or visibility advantages but the evidence (often Google's own on-record statements) contradicts the pitch.

The six overclaimed factors:

1. "Structured data boosts rankings" — false. Google: structured data does not make a site rank better — Mueller (Bluesky, April 13, 2025) — "Structured data won't make your site rank better. It's used for displaying the search features listed in Google's documentation", Rule: structured data is RICH-RESULT eligibility + entity/clarity + machine-readability — NOT a ranking lever; do not promise a ranking lift to clients.
2. "Schema is required for AI Overviews / AI citation" — false. Google: not required; no special schema needed — Google AI optimization guide — "Structured data isn't required for generative AI search, and there's no special schema.org markup you need to add".
3. "You need llms.txt, AI-specific markup, or content chunking" — false. Google's AI guide (June 2026) explicitly lists these as unnecessary; llms.txt is "ignored" — Google AI optimization guide (updated June 15, 2026) — llms.txt is "ignored"; AI-specific markup and content chunking are explicitly listed as unnecessary, Rule: do NOT implement llms.txt, AI-specific markup, or content chunking for Google Search — Google explicitly says these do nothing.
4. "Core Web Vitals are a major ranking lever" — overstated. Tiebreaker-class — Mueller — "We've been pretty clear that Core Web Vitals are not giant factors in ranking"; "relevance is still by far much more important"; CWV is tiebreaker-class.
5. "Perfect Lighthouse / CWV scores lift rankings" — false. Mueller: last few percent "won't change" SEO — Mueller on chasing perfect Lighthouse / CWV scores — getting "those last few percent… your site's SEO generally won't change because of that", Rule: do NOT chase perfect Lighthouse / Core Web Vitals scores — Mueller: last few percent "won't change" SEO; once in the "good" range, stop.
6. "Technical SEO is how you win" — false framing. It is a gate/prerequisite, not a differentiator — "Technical SEO is how you win" is a FALSE FRAMING — it is a gate/prerequisite, NOT a differentiator; once gates are cleared, durable advantage comes from content and earned signals.

Source: Google Search Central documentation; named Google representatives (Mueller); compass_artifact research synthesis.

Confidence: High (each individual overclaim is contradicted by an on-record Google statement or Google doc).

Caveat: Every entry in this category has a vendor or agency commercial incentive behind it. Quarantine vendor claims that map onto this list.