Why so much fuss of having a strong internal linking structure? Why Inlinks are good SEO practice? Here are some of the reasons:

1. Easy navigation:
Internal links are there to help visitors to navigate other pages of the website through them.

2. Provides relevant data to the website visitors and crawlers:
Using internal linking you indicate to end-users and crawlers (Bots) that there is other pages or info on the site that is related to the text they are reading. Doing this will help improving the creditability of the website.

Inlink Structure & Benefits

3. Plays a vital role in decreasing the bounce rate:
This could be a bit controversial point but I do believe that when a visitor reads and scrolls through your website and comes across a link that relates to an identical page or a post that elaborates the topic in bit more depth you can expect a visitor to stay longer on your site. This will in turn, lower your site’s bounce rates.

4) Pass the link juice to other pages:
There is always going to be a case where one of the pages of your website has a higher page rank or authority. You can place a link to a relevant page from the page which has higher page ranking/authority  linking to the page which has a relatively lower page ranking/authority on your website. This will certainly cause in passing the link juice to the linked page. Eventually, page with lower page ranking/authority will start performing better.