This slowdown is almost always caused by automation stacking rather than a single inefficient component. Each record save can trigger record-triggered Flows, Apex triggers, validation rules, roll-ups, and even downstream automation on related objects. Individually these may be lightweight, but together they add measurable execution time.

The issue often worsens because automation is added incrementally. New Flows or triggers are created to handle edge cases without considering existing logic, so the same record may be updated multiple times in one transaction. This leads to repeated evaluations, recalculations, and re-entry into automation chains.