Why do we say Web CAPI is a server to server integration when in reality it is browser - server - server integration?

Why do we say Web CAPI is a server to server integration when in reality it is browser - server - server integration?

Web CAPI enables marketers to send events from their servers to any ad platform directly. It only seems to be like browser - server - server integration, while it is actually a server - to - server integration. The key distinction lies in how the data is ultimately sent. While, server - to - server integration, excludes direct browser involvement in the final data transmission. However, server - to - server integrations are not subject to browser related issues like ad blockers. They offer an enhanced security and data privacy ecosystem.