The secondary and tertiary groups are both your indirect competition.Their products may not be the same as yours, but could satisfy the same need or solve the same problem. You should primarily focus on your direct competitors, but you should watch your indirect competitors. These businesses may move into another group as your business, or theirs, grows and expand product offerings.
The errors in technical SEO are often not obvious, and therefore one of the most popular. Mistakes in robots.txt and 404 pages, pagination and canonical URLs, hreflang tags and 301 redirects, http vs https and www vs non www versions: each of them can seriously spoil all efforts to promote the site. One quality SEO website analysis is enough to solve all the main problems in this part forever.