Do I need a PIM if I already use Shopify?

Not necessarily. Shopify can be sufficient when the catalogue is relatively simple, one team manages it and Shopify can serve as the main product-data source. A PIM becomes more useful when product information comes from many suppliers, needs complex enrichment or approval, supports several brands or markets, or must be syndicated to many channels. The decision should be based on product-data complexity and workflow needs, not SKU count alone. Many businesses can improve governance significantly before introducing another platform.