Origin.
GA4 is the first attribution surface most operators reach for, and the one most CFOs see when they ask where the marketing money went. The numbers are clean, the channels are named, and the credit is assigned to a decimal place. The combination produces a settled feeling. The settled feeling is the problem. The numbers describe what GA4 saw, filtered through what consent mode allowed, modeled where data was missing, and credited according to whichever model the property was set to last quarter.