If you are writing content for the web and you want it to rank highly, you need to think about your competition. Not only does it help focus your SEO efforts but it can often give you ideas on what you need to include on your page.
‘A SERP competitor could have only one page that competes with you, but if that page is ranking above you on an important SERP, they are your competition and you need to understand why they are beating you.’
https://searchengineland.com/search-competition-who-are-you-really-competing-with-338403
If you’re a Marketing Club member then you can find my competitor research process in the SEO Strategy webinar but I’d also check out this article from Andrew Dennis at Search Engine Land that goes through a simple process you can use.