Google's John Mueller has another good one-liner about SEO and Google ranking. He said on Mastodon, "No ranking factor compensates missing relevance, or missing user interest."
He explained, "it's easy to forget that a site doesn't just 'rank' on its own, it ranks for what it's relevant for."
The context around these comments is from the video John released on "Does semantic HTML help Search identify and evaluate content?" In short, semantic HTML helps Google understand your content but it is not a ranking factor and doesn't really help you rank better. That is the relevancy comment.
Here is that video:
Simon Cox responded to John saying, "I do like the line - "it's not a ranking factor but does help us understand the content better." That's a small nuance that is really important but people tend to ignore it!"
John replied on Mastodon "It's a fine line - people often take the 'it helps Google' angle as a reason to hyper-fixate on it, and assume all of these add up to #1 rankings. And with that, it's easy to forget that a site doesn't just 'rank' on its own, it ranks for what it's relevant for. No ranking factor compensates missing relevance, or missing user interest."
Forum discussion at Mastodon.