Collection pages with no text — just a grid of products, nothing for Google to index as relevant to the category
Shopify's default collection page is a product grid. There is no paragraph explaining what the collection contains, who it is for, or what makes it worth choosing over Amazon AU or Catch. Google needs content to classify and rank a page. A collection page with no text competes against category pages from retailers that have buying guides, FAQs, and descriptive copy — and it loses.