Full Answer

ETL tools work for orders, products, and customers via the WooCommerce REST API, but they cannot capture behavioral events because the API doesn't expose them — no add-to-carts, no checkout steps, no scroll depth. GA4 BigQuery export is free and captures behavior, but the 24-72 hour delay and 1M events/day batch limit make it unusable for real-time decisions, and ad blockers strip 15-30% of events before they ever reach GA4. Direct event streaming through a server-side tool like Transmute Engine writes raw events to BigQuery via the Streaming Insert API in seconds, with no GTM container required and no Google middleman. The decision frame is what data you actually need: historical records, sampled behavior, or the complete event stream.