A headless build is a good fit when a WooCommerce (or other) store needs a storefront experience the default theme can't deliver — for example a highly custom UI, a non-WordPress frontend framework, multiple storefronts sharing one backend, or very specific performance targets — and the team has the budget and developers to maintain a second codebase. It is usually not worth it for a standard catalog store that a theme and page builder can already serve: headless adds a second application, a build pipeline and API integration work that a themed WooCommerce store does not need.