Adjudicating the vendor-versus-Google gap on schema — schema-plugin sellers, SEO-tool vendors, "technical SEO" agencies market schema as a ranking and AI-citation booster; contradicted by Google's explicit on-record statements; even the indirect CTR-routing argument (Berreby) is NDA-covered and concedes no direct ranking effect

Claim: Schema-plugin sellers, SEO-tool vendors, and "technical SEO" agencies frequently market structured data as a ranking and AI-citation booster.

This is a quarantined claim: each such seller has a direct commercial incentive to overstate schema's value.

One prominent contrarian to Google's position (Elie Berreby) argues schema → CTR → rankings. The argument:

• is indirect (it concedes schema is NOT a direct ranking factor and routes through CTR)
• is based on undisclosed NDA-covered data
• is contradicted by Google's explicit statements (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", 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")

Verdict: implement structured data for the rich-result features your pages genuinely map to — it is worthwhile hygiene — but do not expect or promise a ranking lift or AI-citation guarantee.

Source: Compass_artifact research synthesis; vendor marketing review; Elie Berreby published position.

Confidence: Verified. Grade A on the verdict.

Caveat: This is the inoculation copy for client conversations where the prospect has just been pitched schema-as-ranking-lever by a previous agency. The rule is Rule: structured data is RICH-RESULT eligibility + entity/clarity + machine-readability — NOT a ranking lever; do not promise a ranking lift to clients.