Breadcrumbs are supposed to be hierarchical, describing the route a user takes to get to a page (comes from the story of Hansel and Gretel I believe).
Taking the first result in @dmitry_fedyuk’s screenshot - the arrows on the google search results make it seem like “webhook” is a subcategory of “Square”, “square” is a subcategory of “webhook”, and “payment” is a subcategory of “square”. This is clearly not the case, and could be confusing.
Categories are the hierarchical structure in discourse, so in my opinion tags should not be marked as breadcrumbs.