Event tracking captures what people do, not just which pages they view. A deliberate event schema names each action consistently and records useful properties, so funnels, cohorts, and attribution reports can answer real questions.
Tracking should be designed backwards from decisions and should avoid collecting sensitive personal data unnecessarily. Undocumented, ad hoc events are the main reason analytics becomes untrustworthy. A short written schema, owned by one person, keeps naming consistent as the product grows.