Google Ranking Factor – Links within the domain
Links within a site count toward a page’s link profile, so all navigation links and contextual links are positive votes for the sites pages.
I believe a page’s link profile should be at least equal to the total number of pages within the website multiplied by 2 as a minimum.
Check Google Search Console for data on the current links discovered within your site to your individual pages. The typical observation is that the home page usually has the most internal links, and blog posts usually have the least.
That’s a key problem for blog posts, especially if you are relying on them for SEO.
You need to elevate key SEO content to be discovered and crawled.
This would be achieved by having all pages accessible within the navigation structure as part of the page template. And then by adding links in context, a page can also gain strength through the link anchor text, the immediate context around the link anchor, and the wider page context.
Use aggregated elements like blog widgets or ‘related articles’ functions to increase the link counts for deeper pages.
A rich navigation and contextual link count for a site might be around 5 to 50 times the number links as pages in the site, so a healthy site with 20 pages might expect to have around 100+ links pointing to every page.