One SEO professional asked John Mueller about internal linking and using structured data for breadcrumbs.
Their main question is: if one has structured data for breadcrumbs setup, is internal linking still important for SEO?
John answered that yes, absolutely. Internal linking is still super critical for SEO.
John believes it’s one of the biggest things you can do on your site to guide Google, and guide visitors to the pages that you think are important.
And what you think is important is totally up to you. You can decide to make things important where you earn the most money, or you can make things important where you’re the strongest competitor, or maybe you are the weakest competitor.
With internal linking, you can really kind of focus things on those directions and those parts of your site.
And this is not something that you can just replace with structured data.
So just because there is structured data in a page somewhere, that is not a replacement for normal internal linking.
Even if in the structured data, you also provide URLs, Google does not use these URLs in the same way as they would use normal internal links on a page.
So, it’s not the case that hreflang annotations replace links between country versions or breadcrumb annotations, nor do they replace links between different levels of a website.
You really have to have normal HTML links between the different parts of your site in addition to this markup.
This happens at approximately the 25:15 mark in the video.