Full Answer

GA4 does three things well: real-time dashboards, audience building for Google Ads, and pre-configured reports that non-technical users can navigate without SQL. Replacing those functions with raw BigQuery queries would require building a custom reporting layer — possible but unnecessary for most stores.

What GA4 cannot do is provide a complete event record. GA4 applies consent-mode filtering that excludes events from users who decline cookies, samples data at high traffic volumes, and enforces retention policies that delete event-level data after 14 months maximum. The BigQuery export from GA4 inherits these limitations — it exports what GA4 captured, not what actually happened on your site.

A Data Tree captures events server-side at the WooCommerce hook level, bypassing consent-mode gaps and ad blocker losses that affect GA4. The raw events flow into your own BigQuery warehouse with no sampling, no retention expiry, and no consent-mode filtering of the server-side stream. After twelve months, your Data Tree contains a dataset that GA4's own BigQuery export cannot replicate.

The practical architecture keeps both. GA4 handles daily traffic monitoring, real-time debugging, and Google Ads audience integration. Your Data Tree handles cohort analysis, lifetime value calculations, channel attribution comparisons, and the long-term data accumulation that AI marketing tools will need. One is a dashboard. The other is an asset.