Over the years we have helped out on a number of different WooCommerce sites and almost all have had the same issue (they required a lot of maintenance and developer support). While they were sold on the premise of lower cost they often wind up costing more in extra plugin fees and maintenance support. Do not even get us started on how many have outdated plugins in the bucketload.
Shopify powers over 4.6 million stores worldwide and has processed more than $700 billion in sales. That scale matters because it means the infrastructure is battle-tested and the payment systems are reliable. When you build on Shopify you are building on something that handles Black Friday traffic for thousands of stores simultaneously.
Mobile commerce now accounts for more than 70% of global ecommerce traffic. The Shopify checkout is optimised for mobile out of the box with one-tap payments and Apple Pay and Google Pay. This creates a streamlined flow that removes every unnecessary step between a customer wanting something and actually buying it. WooCommerce can be made mobile-friendly but it requires deliberate effort and the right theme whereas with Shopify it is the default.
Then there is the maintenance burden. The average WooCommerce store runs on 20 or more plugins and each of these needs individual updates and compatibility testing. Plugin issues are one of the leading causes of WordPress downtime. Shopify has no plugins to maintain because updates happen automatically at the platform level and your store keeps running.