Minimizing click depth improves SEO by presenting search engines with the relative importance of your pages, by how few clicks it takes to get there from your homepage.
As John Mueller says, “If your homepage is generally the strongest page on your website, and from the homepage it takes multiple clicks to actually get to one of these stores (pages), then that makes it a lot harder for us to understand that these stores are actually pretty important.”
A simple way to improve link depth for an important page is to create a subcategory under your navigation that shows the link directly on your homepage. You can also link to the page from the homepage’s body in a logical way. Of course, too many links dilutes the value of this practice.