GA as source of truth: consented, first-party, modelled data
Third-party data is going away; whatever you collect yourself, with consent, is what you will measure with.
Three levers: respect consent and regional rules such as GDPR, ingest first-party data from web, app and offline (a store associate signing the shopper in on an iPad ties the store visit to the same identity), and use modelling where cookies are refused. Collect and enrich, derive insights, take action: a GA segment can be pushed back into Google Ads, and high-volume data exported to BigQuery. Predictive features flag anomalies and estimate purchase, churn and revenue probability; a marketer behind target can see a two-week revenue forecast and move budget early.
Explains why GA setup is a marketing job, not just an analytics one.