I have come across many eCommerce websites, often large established ones, which have many Product Categories which do not appear within any of their Navigational Links. Furthermore, I cannot seem to 'find' their Product Category, from the Homepage at all.
One example being:
https://www.etsy.com/market/kitchen_wall_art
Obviously, this is a Product Category page. Ignoring the search box, I would not know where to go, if I started off from the Homepage, looking for 'Kitchen Wall Art'. Given they are ranking for the relevant Keyword here, are Etsy integrating some strategy that I am overlooking or simply do not keep in mind Navigation when it comes to many of their Product Categories?
The actual link, which appeared in the search results for 'Kitchen Wall Art', was:
https://www.etsy.com/uk/market/kitchen%20wall%20art
This leads me onto the next question.
How is this link appearing in the search engines, despite it having a Canonical URL to:
https://www.etsy.com/market/kitchen_wall_art
I realise that a rel=noindex should be used, to tell search engines to not index a page, but if the rel=canonical has been used, shouldn't the latter page naturally rank higher?
rel=canonicalis a guideline as far a Google is concerned and they make their own determination as to which page is better. See section 'Google chose different canonical than user' here.