Still can't improve seo on shopify - what am i missing?

Product pages with the manufacturer's description copied word for word. That's the usual one - hundreds of other stores have the exact same text, so there's no reason to rank yours. Rewrite descriptions for your best sellers first. Also check collection pages, they're often what should rank for the broad terms but most stores leave them with a title and a grid and nothing else. A short paragraph above the products helps. And fill in the search engine listing title and description on each product, the default just copies the product name.