When most designers design websites, they don't pay much attention to links. As long as the link works and takes users to the right page, everything is fine.
Improve the accuracy of your website analytics by opening only external links in new tabs.
"Links that take users to different websites should open in new tabs. Links that take users to a different page on the same website should open in the same tab. If you’re opening external links in the same tab as your site, this affects both you and your users. You not only experience inaccurate analytics and make your website work harder, but you also make your users work harder and slower. In a world today where links dominate the web, making your links open the right way is almost as important linking to the right page."