Layered navigation generates unlimited junk URLs
Magento's layered navigation creates a unique URL for every filter combination a shopper can select. A UK fashion retailer with colour, size, brand, material, and occasion filters across 100 categories can generate hundreds of thousands of crawlable filter pages — most duplicating the parent category, none with ranking value. Google's crawl budget on competitive UK retail domains is significant but finite. Junk filter URLs consume budget that should go to category and product pages competing against the major UK retail domains.