The gist is that addressing not only common topics around your content’s theme, but adding unique information, could be a ranking factor.
Anecdotally, my natural bodybuilding blog, a hobby site allowing me to conduct SEO experiments as well, ranks better than expected. This happens despite lacking countless backlinks versus my competition. I know this occurs in part since I do a thorough job of covering subjects yet add new insights.
Competitor research is a powerful way to improve SEO, since ranking signals differ based on search query. Nonetheless, it’s not enough to just match their content… do it better by adding something distinct!