The claim
Content created primarily for search engines rather than to satisfy users can reduce a site's overall performance, whereas people-first helpful content is favoured.
What the evidence shows
Google's 'Creating helpful, reliable, people-first content' guidance and the helpful content system describe a site-level assessment: large amounts of unhelpful content can affect how the whole site performs. It provides self-assessment questions around expertise, first-hand experience, purpose and whether a user would feel satisfied after reading.