Also, the ticket and the commits can provide answers to the same questions without being redundant. The answers are just at a different level of abstraction and

Also, the ticket and the commits can provide answers to the same questions without being redundant. The answers are just at a different level of abstraction and for different readers. Tickets usually describe product-level decisions, while commits describe implementation-specific details. E.g. a ticket may discuss alternative user flows, while a related commit explains why a specific algorithm, module, or default configuration value was used.